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"chemical element" Definitions
  1. a simple chemical substance that consists of atoms of only one type and cannot be split by chemical means into a simpler substance. Gold, oxygen and carbon are all chemical elements.
"chemical element" Synonyms
element

448 Sentences With "chemical element"

How to use chemical element in a sentence? Find typical usage patterns (collocations)/phrases/context for "chemical element" and check conjugation/comparative form for "chemical element". Mastering all the usages of "chemical element" from sentence examples published by news publications.

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"So if the chemical element is going to be called something, why not Lemmium?"
MA-XRF images showing the distribution of one chemical element over the paint surface.
The gas is a chemical element with the symbol He and atomic number 2.
Zinc is a chemical element whose symbol is Zn and atomic number is 343.
It also screws up the name of a vital chemical element needed to power NASA spacecraft.
Tennessine is a superheavy artificial chemical element, of which only a few atoms have ever been made.
"Lead is a chemical element for which toxicity in humans has been well documented," the FDA wrote.
Photo: GettyHelium is an essential chemical element used in MRI scanners, rocket fuel tanks, and floating party balloons.
The chemical element strontium is a heavy alkaline earth metal that is about seven times heavier than carbon.
And it is the most abundant chemical element in the universe, so you'd think we'd have all we need.
If your experience of the world could be violently broken down to a single chemical element, it would be chlorine.
The ATOMIC NUMBER of an atom is the "number of a chemical element in the periodic system," according to Brittanica.
"Lead is a chemical element for which toxicity in humans has been well-documented," the agency wrote, as reported by The Hill.
Titanium is a chemical element that brings completely new features to regular metals, making it possible for new materials to be crafted.
After not exactly filling the sky with blimps, the 50s and 60s saw a boom in industrial use of the chemical element.
Seemingly diverse problems, but a common thread connects them: human disruption of how a single chemical element, nitrogen, interacts with the environment.
SILICON VALLEY, the heartland of America's technology industry, takes its name from the chemical element that is the most important ingredient in microchips.
In St. Joseph, the state health officer said, the cause of brown water is likely iron -- a chemical element with no federal limits.
Though these are low in calories, their high levels of the chemical element can cause clogged pores and acne, according to Women's Health.
Today, multiple prestigious awards in physics are named in honor of Meitner and she even has a chemical element -- meitnerium -- named after her.
This allows scientists to construct images of a painting using one chemical element at a time, such as lead, copper, iron and mercury.
Lithium, a powdery chemical element that is extracted from igneous rock and mineral water, is also used in batteries, lubricating grease and rocket fuel.
Cosmic Quest also provides players with the wrong name for Plutonium 238, a vital chemical element NASA uses to power Radioisotope Thermoelectric Generators, or RTGs.
An isotope is a version of a chemical element that has the same number of protons but a different number of neutrons in the nucleus.
The Commerce Department is opening an investigation into whether imports of uranium — the chemical element that fuels nuclear power — pose a risk to national security.
By the end of summer 2016, over 500 Starbucks locations will serve nitro coffee, a cold brew that has been infused with nitrogen, chemical element number 7.
Arsenic, a chemical element known to cause cancer and skin lesions, was found to be emitted at rates 37 times what the previous Radford burn permit estimated.
"Each chemical element leaves a unique pattern of dark bands at specific wavelengths in these spectra, like fingerprints," Daniel Zucker, from Macquarie University and the AAO, explained in a statement online.
At the dawn of the atomic age, U.S. government incentives and trade barriers sparked a gold rush for uranium, the chemical element that was fueling the nuclear arms race at the time.
Why it matters: Without helium, doctors wouldn't be able to give their patients noninvasive MRI scans, and scientists need chemical element to pressurize fuel tanks for space travel and satellite instruments, per USA Today.
One group at the University of Maryland lined up ten trapped ytterbium ions (ytterbium is just a chemical element) and shined them with periodic laser pulses to mostly, but not completely, flip the ions' spins.
Concentrations of phosphorous fell by a third from 2006 to 2014 in 862 freshwater lakes around China, although they remain above clean water levels, according to the report about the chemical element in the journal Nature Geoscience.
The research, sponsored by the U.S. National Aeronautics and Space Administration, is based on measurements of the chemical element argon at different altitudes in the thinning atmosphere around Mars, which MAVEN has been assessing since October 2015.
The Obama administration introduced a rule (that had been crafted over nearly 40 years) to reduce exposure to beryllium, a chemical element that has caused "Chronic Beryllium Disease," a type of bacterial lung disease that kills approximately 100 people each year.
The rover's arm includes five electrical motors and five joints, and its turret will include cameras, a life-detection instrument known as SHERLOC, a chemical element detector and a percussive drill and coring mechanism, according to the Jet Propulsion Laboratory.
Electric cars and smartphones of the future could be powered by supervolcanoes like Yellowstone after scientists discovered that ancient deposits within them contain huge reservoirs of lithium—a chemical element used to make lithium-ore batteries, supplies of which are increasingly dwindling.
The presence of this chemical element suggests that high levels of free-floating oxygen once existed on Mars, and that in addition to having a warmer climate and lakes of liquid water, this planet was once quite Earth-like in terms of its chemical composition.
Others, like Stefano Passerini, director of the Helmholtz Institute in Ulm, a battery research center in Germany, says the next generation of small-scale storage will be sodium-ion batteries, which, unlike lithium batteries, don't require cobalt, a mined chemical element that is ever-harder to find.
Table for Three The first two things you notice when you walk into Bill Gates's private office, just outside Seattle, are a wall-size installation of the periodic table with a sample of each chemical element in its own glass-fronted vitrine and handsome bookshelves that reach nearly to the ceiling.
The magazine now exists online. The artificial chemical element promethium is named after Prometheus.
In 1947 they named it technetium, as it was the first artificially synthesized chemical element.
However, Meitner received many other honours, including the naming of chemical element 109 meitnerium in 1997.
For more detailed information about the origins of element names, see List of chemical element name etymologies.
Caesium is the most electropositive chemical element. The caesium ion is also larger and less "hard" than those of the lighter alkali metals.
The rover carries an alpha particle X-ray spectrometer and an infrared spectrometer, intended to analyze the chemical element composition of lunar samples.
Nickel allergy or nickel allergic contact dermatitis (Ni-ACD) is a form of allergic contact dermatitis (ACD) caused by exposure to the chemical element nickel.
Seaborgium was named in his honour, making him the only person, along Albert Einstein and Yuri Oganessian, for whom a chemical element was named during his lifetime.
Herminiimonas arsenicoxydans is a species of ultramicrobacteria. First reported in 2006, it was isolated from industrial sludge and is able to oxidise the toxic chemical element arsenic.
After his death in 1937, he was buried in Westminster Abbey near Sir Isaac Newton. The chemical element rutherfordium (element 104) was named after him in 1997.
Johan August Arfwedson (12 January 1792 - 28 October 1841) was a Swedish chemist who discovered the chemical element lithium in 1817 by isolating it as a salt.
Experimental measurement by Henry Moseley of this radiation for many elements (from ) showed the results as predicted by Bohr. Both the concept of atomic number and the Bohr model were thereby given scientific credence. The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element. The atomic number uniquely identifies a chemical element.
Seaborgium was named in his honour, making him the only person, along with Albert Einstein and Yuri Oganessian, for whom a chemical element was named during his lifetime.
Oswald Helmuth Göhring, also known as Otto Göhring, (1889 - 1915) was a German chemist who, with his teacher Kasimir Fajans, co-discovered the chemical element protactinium in 1913.
Argon fluorohydride (systematically named fluoridohydridoargon) or argon hydrofluoride is an inorganic compound with the chemical formula HArF (also written ArHF). It is a compound of the chemical element argon.
Heteronuclear molecules A heteronuclear molecule is a molecule composed of atoms of more than one chemical element. For example, a molecule of water (H2O) is heteronuclear because it has atoms of two different elements, hydrogen (H) and oxygen (O). Similarly, a heteronuclear ion is an ion that contains atoms of more than one chemical element. For example, the carbonate ion (CO32−) is heteronuclear because it has atoms of carbon (C) and oxygen (O).
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( )."hydrargyrum" . Random House Webster's Unabridged Dictionary.
The Iron Man 2 features a makeshift particle accelerator used by Tony Stark to create a new chemical element, more biologically inert than the palladium used in the arc reactor.
Ira Sprague Bowen (December 21, 1898 - February 6, 1973) was an American physicist and astronomer. In 1927 he discovered that nebulium was not really a chemical element but instead doubly ionized oxygen.
Clarke number or clarke is the relative abundance of a chemical element, typically in Earth's crust. The technical definition of "Earth's crust" varies among authors, and the actual numbers also vary significantly.
Stable isotopes of neon are produced in stars. Neon's most abundant isotope 20Ne (90.48%) is created by the nuclear fusion of carbon and carbon in the carbon-burning process of stellar nucleosynthesis. This requires temperatures above 500 megakelvins, which occur in the cores of stars of more than 8 solar masses. Neon is abundant on a universal scale; it is the fifth most abundant chemical element in the universe by mass, after hydrogen, helium, oxygen, and carbon (see chemical element).
Even though it is not a chemical element, the neutron is included in this table.Nudat 2. Nndc.bnl.gov. Retrieved on 2010-12-04. The free neutron has a mass of 939,565,413.3 eV/c2, or , or .
The rover carried an alpha particle X-ray spectrometer (APXS) and an infrared spectrometer, intended to analyze the chemical element composition of lunar samples. The APXS was the only payload on the robotic arm.
Separate atoms of a sample present in the flame can emit only due to electronic transitions between different atomic energy levels. Those transitions emit light of very specific frequencies, characteristic of the chemical element itself. Therefore, the flame gets the color, which is primarily determined by properties of the atomic energy shells of the chemical element of the substance being put into flame. The flame test is a relatively easy experiment to set up and thus is often demonstrated or carried out in science classes in schools.
Latimer diagram of Manganese A Latimer diagram of a chemical element is a summary of the standard electrode potential data of that element. This type of diagram is named after Wendell Mitchell Latimer, an American chemist.
Porous silicon (abbreviated as "PS" or "pSi") is a form of the chemical element silicon that has introduced nanopores in its microstructure, rendering a large surface to volume ratio in the order of 500 m2/cm3.
Atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy vol. 1 (1808) In the early 1800s, John Dalton compiled experimental data gathered by himself and other scientists and discovered a pattern now known as the "law of multiple proportions". He noticed that in chemical compounds which contain a particular chemical element, the content of that element in these compounds will differ by ratios of small whole numbers. This pattern suggested to Dalton that each chemical element combines with others by some basic and consistent unit of mass.
Kazimierz Fajans (Kasimir Fajans in many American publications; 27 May 1887 – 18 May 1975) was a Polish American physical chemist of Polish-Jewish origin, a pioneer in the science of radioactivity and the discoverer of chemical element protactinium.
Iodine is a chemical element with the symbol I and atomic number 53. The name is from Greek ioeidēs, meaning violet or purple, due to the color of elemental iodine vapor.Online Etymology Dictionary, s.v. iodine. Retrieved 2012-02-07.
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, gray-white, strong transition metal that resembles titanium.
Tungsten, or Wolfram,wolfram on Merriam-Webster.wolfram on Oxford Dictionaries. is a chemical element with the symbol W and atomic number 74. The name tungsten comes from the former Swedish name for the tungstate mineral scheelite, which means "heavy stone".
The English word ‘stannary’ is derived from the Middle English stannarie, through Medieval Latin stannaria (‘tin mine’), ultimately from Late Latin stannum (‘tin’) (cf. the symbol for the chemical element Sn). The native Cornish word is sten and tin-workings stenegi.
After his death, the Regents of the University of California renamed the Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory after him. Chemical element number 103 was named lawrencium in his honor after its discovery at Berkeley in 1961.
Neon is a chemical element with the symbol Ne and atomic number 10. It is a noble gas.Group 18 refers to the modern numbering of the periodic table. Older numberings described the rare gases as Group 0 or Group VIIIA (sometimes shortened to 8).
RIXS is element and orbital specific: chemical sensitivity arises by tuning to the absorption edges of the different types of atoms in a material. RIXS can even differentiate between the same chemical element at sites with inequivalent chemical bondings, with different valencies or at inequivalent crystallographic positions as long as the X-ray absorption edges in these cases are distinguishable. In addition, the type of information on the electronic excitations of a system being probed can be varied by tuning to different X-ray edges (e.g., K, L or M) of the same chemical element, where the photon excites core-electrons into different valence orbitals.
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard and brittle transition metal. Chromium is the main additive in stainless steel, to which it adds anti-corrosive properties.
In chemistry, a free element is a chemical element that is not combined with or chemically bonded to other elements. Examples of elements which can occur as free elements include the oxygen molecule (O) and carbon.A. Earnshaw and Norman Greenwood. Chemistry of the Elements (Second Edition) .
Iridium 77 is a communications Satellite which is part of a satellite constellation known as Iridium, named after the 77th chemical element of the periodic table, iridium. It was launched in 1998 and as of 2014, operational. It is owned and funded by Iridium, a communications company.
Tellurium is a chemical element with the symbol Te and atomic number 52\. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in native form as elemental crystals.
Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is various. The largest variety is used in research (e.g. in chemistry where atoms of "marker" nuclide are used to figure out reaction mechanisms).
Studies of the "radioactivity", that soon revealed the phenomenon of radioactive decay, provided another argument against considering chemical elements as fundamental nature's elements. Despite these discoveries, the term atom stuck to Dalton's (chemical) atoms and now denotes the smallest particle of a chemical element, not something really indivisible.
Gadolinium is a chemical element with the symbol Gd and atomic number 64. Gadolinium is a silvery-white metal when oxidation is removed. It is only slightly malleable and is a ductile rare-earth element. Gadolinium reacts with atmospheric oxygen or moisture slowly to form a black coating.
The term iridium anomaly commonly refers to an unusual abundance of the chemical element iridium in a layer of rock strata at the Cretaceous–Paleogene (K-Pg) boundary. The unusually high concentration of a rare metal like iridium is often taken as evidence for an extraterrestrial impact event.
Carbon (from "coal") is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust.
Argon is a chemical element with the symbol Ar and atomic number 18\. It is in group 18 of the periodic table and is a noble gas.In older versions of the periodic table, the noble gases were identified as Group VIIIA or as Group 0. See Group (periodic table).
This is a form of nuclear decay. The number of protons in the nucleus is the atomic number and it defines to which chemical element the atom belongs. For example, any atom that contains 29 protons is copper. The number of neutrons defines the isotope of the element.
Decipium was the proposed name for a new chemical element isolated by Marc Delafontaine from the mineral samarskite. He published his discovery in 1878 and a follow-up paper in 1881. Considered to be in the cerium group of rare earths.Harmsworth's Universal Encyclopaedia vol X, 1922 p6493 Rare Earths.
GRS instruments supply data on the distribution and abundance of chemical elements, much as the Lunar Prospector mission did on the moon. In this case, the chemical element thorium was mapped, with higher concentrations shown in yellow/orange/red in the left-hand side image shown on the right.
Rhodium is a chemical element with the symbol Rh and atomic number 45. It is an ultra-rare, silvery-white, hard, corrosion-resistant, and chemically inert transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope, 103Rh.
The flag of Polevskoy consists of the Venus symbol (♀), which represents the chemical element copper, the character Lizard Queen of Russian folklore, the symbolic representation of the Stone Flower from the story of the same name, and the eight-pointed star, the brand of the Seversky Pipe Plant.
Iron, shown here as fragments and a 1 cm3 cube, is an example of a chemical element that is a metal. A metal in the form of a gravy boat made from stainless steel, an alloy largely composed of iron, carbon, and chromium A metal (from Greek μέταλλον métallon, "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically malleable (they can be hammered into thin sheets) or ductile (can be drawn into wires). A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride.
Since the bulk density of a solid chemical element is strongly related to its molar mass, there exists a noticeable inverse correlation between a solid's density and its specific heat capacity on a per-mass basis. This is due to a very approximate tendency of atoms of most elements to be about the same size, despite much wider variations in density and atomic weight. These two factors (constancy of atomic volume and constancy of mole-specific heat capacity) result in a good correlation between the volume of any given solid chemical element and its total heat capacity. Another way of stating this, is that the volume-specific heat capacity (volumetric heat capacity) of solid elements is roughly a constant.
In the 19th century, John Dalton, through his work on stoichiometry, concluded that each chemical element was composed of a single, unique type of particle. Dalton and his contemporaries believed those were the fundamental particles of nature and thus named them atoms, after the Greek word atomos, meaning "indivisible" or "uncut".
Davyum was the proposed name for a chemical element found by chemist Serge Kern in 1877. It was shown that the material was a mixture of iridium and rhodium. In 1950 it was proposed that the new metal might also have contained rhenium, which had not been discovered in Kern's time.
Atoms are the smallest neutral particles into which matter can be divided by chemical reactions. An atom consists of a small, heavy nucleus surrounded by a relatively large, light cloud of electrons. Each type of atom corresponds to a specific chemical element. To date, 118 elements have been discovered or created.
A simple but important result within this setting is that entropy is uniquely determined, apart from a choice of unit and an additive constant for each chemical element, by the following properties: It is monotonic with respect to the relation of adiabatic accessibility, additive on composite systems, and extensive under scaling.
The remainder were made possible by the action of living organisms, particularly the addition of oxygen to the atmosphere. This paper was followed over the next few years by several studies concentrating on one chemical element at a time and mapping out the first appearances of minerals involving each element.
Dietitians may recommend that minerals are best supplied by ingesting specific foods rich with the chemical element(s) of interest. The elements may be naturally present in the food (e.g., calcium in dairy milk) or added to the food (e.g., orange juice fortified with calcium; iodized salt fortified with iodine).
Ecosystem models are mathematical representations of ecosystems. Typically they simplify complex foodwebs down to their major components or trophic levels, and quantify these as either numbers of organisms, biomass or the inventory/concentration of some pertinent chemical element (for instance, carbon or a nutrient species such as nitrogen or phosphorus).
Lithium (from ) is a chemical element with the symbol Li and atomic number 3\. It is a soft, silvery-white alkali metal. Under standard conditions, it is the lightest metal and the lightest solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in mineral oil.
The speed of sound in any chemical element in the fluid phase has one temperature-dependent value. In the solid phase, different types of sound wave may be propagated, each with its own speed: among these types of wave are longitudinal (as in fluids), transversal, and (along a surface or plate) extensional.
The table here shows a widely used layout. Other forms (discussed below) show different structures in detail. Each chemical element has a unique atomic number (Z) representing the number of protons in its nucleus. Most elements have differing numbers of neutrons among different atoms, with these variants being referred to as isotopes.
Dubnium is a synthetic chemical element with the symbol Db and atomic number 105. Dubnium is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 28 hours. This greatly limits the extent of research on dubnium. Dubnium does not occur naturally on Earth and is produced artificially.
Several other countries have also issued postage stamps depicting Bohr. In 1997, the Danish National Bank began circulating the 500-krone banknote with the portrait of Bohr smoking a pipe. An asteroid, 3948 Bohr, was named after him, as was the Bohr lunar crater and bohrium, the chemical element with atomic number 107.
An octatomic element is a chemical element that, when standard conditions for temperature and pressure is stable, is in a configuration of eight atoms grouped together. The canonical example is sulfur, S8, but red selenium is also an octatomic element stable at room temperature. Octaoxygen is also known, but it is extremely unstable.
The bromodomain was identified as a novel structural motif by John W. Tamkun and colleagues studying the drosophila gene Brahma/brm, and showed sequence similarity to genes involved in transcriptional activation. The name "bromodomain" is derived from the relationship of this domain with Brahma and is unrelated to the chemical element bromine.
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust.
Since the bulk density of a solid chemical element is strongly related to its molar mass (usually about 3R per mole, as noted above), there exists noticeable inverse correlation between a solid's density and its specific heat capacity on a per-mass basis. This is due to a very approximate tendency of atoms of most elements to be about the same size, despite much wider variations in density and atomic weight. These two factors (constancy of atomic volume and constancy of mole-specific heat capacity) result in a good correlation between the volume of any given solid chemical element and its total heat capacity. Another way of stating this, is that the volume-specific heat capacity (volumetric heat capacity) of solid elements is roughly a constant.
This was the first time a chemical element was discovered on an extraterrestrial body before being found on the earth. Lockyer and the English chemist Edward Frankland named the element after the Greek word for the Sun, ἥλιος (helios).Oxford English Dictionary (1989), s.v. "helium". Retrieved 16 December 2006, from Oxford English Dictionary Online.
Arsenic is a chemical element with the symbol As and atomic number 33\. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but only the gray form, which has a metallic appearance, is important to industry.
An oxyanion, or oxoanion, is an ion with the generic formula (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. The formulae of simple oxyanions are determined by the octet rule. The corresponding oxyacid of an oxyanion is the compound .
Swedish chemist Carl Gustaf Mosander discovered terbium as a chemical element in 1843. He detected it as an impurity in yttrium oxide, Y2O3. Yttrium and terbium, as well as erbium and ytterbium, are named after the village of Ytterby in Sweden. Terbium was not isolated in pure form until the advent of ion exchange techniques.
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard-brittle, grayish-white metalloid in the carbon group, chemically similar to its group neighbours silicon and tin. Pure germanium is a semiconductor with an appearance similar to elemental silicon. Like silicon, germanium naturally reacts and forms complexes with oxygen in nature.
Other things associated with water and phlegm in ancient and medieval medicine included the season of Winter, since it increased the qualities of cold and moisture, the phlegmatic temperament, the feminine and the western point of the compass. In alchemy, the chemical element of mercury was often associated with water and its alchemical symbol was a downward-pointing triangle.
Helium production is expected to decline along with natural gas production in these areas. Helium, which is the second-lightest chemical element, will rise to the upper layers of Earth's atmosphere, where it can forever break free from Earth's gravitational attraction. Approximately 1,600 tons of helium are lost per year as a result of atmospheric escape mechanisms.
Outstanding physicists of the 20th century including Nikolay Bogolyubov, Georgy Flyorov, Vladimir Veksler, and Bruno Pontecorvo used to work at the institute. A number of elementary particles and nuclei of transuranium elements (most recently, element 117) have been discovered and investigated there, leading to the honorary naming of chemical element 105 dubnium (Db) for the town.
Tellurium is a chemical element that has the symbol Te and atomic number 52. A brittle, mildly toxic, rare, silver-white metalloid which looks similar to tin, tellurium is chemically related to selenium and sulfur. It is occasionally found in native form, as elemental crystals. Tellurium is far more common in the universe than on Earth.
Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare-earth element with a metallic silver luster. Dysprosium is never found in nature as a free element, though it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy.
Isotopes of a chemical element differ only in the mass number. For example, the isotopes of hydrogen can be written as 1H, 2H and 3H, with the mass number superscripted to the left. When the atomic nucleus of an isotope is unstable, compounds containing this isotope are radioactive. Tritium is an example of a radioactive isotope.
Element Eighty was an American four-piece nu metal band from Tyler, Texas, United States. The band formed in 2000. The band split in 2006, only to be reunited a few months later in 2007. Their first album was named after the chemical element mercury, which has number eighty in the Periodic Table of the Elements.
Thallium is a chemical element with the symbol Tl and atomic number 81. It is a gray post-transition metal that is not found free in nature. When isolated, thallium resembles tin, but discolors when exposed to air. Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production.
The concept of unobtainium is often applied hand-waving, flippantly or humorously. The word unobtainium derives humorously from unobtainable with the suffix -ium, the conventional designation for a chemical element. It pre-dates the similar- sounding IUPAC systematic element names, such as ununennium. An alternative spelling, unobtanium is sometimes used based on the spelling of metals such as titanium.
A homocycle or homocyclic ring is a ring in which all atoms are of the same chemical element. A heterocycle or heterocyclic ring is a ring containing atoms of at least two different elements, i.e. a non-homocyclic ring. A carbocycle or carbocyclic ring is a homocyclic ring in which all of the atoms are carbon.
Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13 (boron group).
Compounds of carbon are defined as chemical substances containing carbon.Organic Chemistry by Abraham William SimpsonEncyclopedia of Inorganic Chemistry Bruce King Ed. Second Edition More compounds of carbon exist than any other chemical element except for hydrogen. Organic carbon compounds are far more numerous than inorganic carbon compounds. In general bonds of carbon with other elements are covalent bonds.
A base anhydride is an oxide of a chemical element from group 1 or 2 (the alkali metals and alkaline earth metals, respectively). They are obtained by removing water from the corresponding hydroxide base. If water is added to a base anhydride, a corresponding hydroxide salt can be re-formed. Base anhydrides are not Brønsted–Lowry bases because they are not proton acceptors.
Bismuth is a chemical element that has the symbol Bi and atomic number 83. This heavy, brittle, white crystalline trivalent other metal has a pink tinge and chemically resembles arsenic and antimony. Of all the metals, it is the most naturally diamagnetic, and only mercury has a lower thermal conductivity. It is also generally considered as the last naturally occurring non- radioactive element.
Manga Basket-Ball, also known as Manga BB or simply Manga, is a Gabonese basketball club based in Moanda. The club has been active internationally representing Gabon in the FIBA Africa Basketball League. The team is founded and sponsored by manganese mining company Compagnie minière de l'Ogooué (COMILOG). The club name is derived from manganese, which is the chemical element the company mines.
Copernicium is a synthetic chemical element with the symbol Cn and atomic number 112. Its known isotopes are extremely radioactive, and have only been created in a laboratory. The most stable known isotope, copernicium-285, has a half-life of approximately 28 seconds. Copernicium was first created in 1996 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.
In spite of the name, pencil leads do not contain the toxic chemical element lead, but are typically made with graphite and clay, or plastic polymers. Compared to standard pencils, mechanical pencils have a smaller range of marking types, though numerous variations exist. Most mechanical pencils can be refilled, but some inexpensive models are meant to be disposable and are discarded when empty.
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is silvery with a hint of blue; it tarnishes to a dull gray color when exposed to air.
Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare-earth element. Holmium was discovered through isolation by Swedish chemist Per Theodor Cleve and independently by Jacques-Louis Soret and Marc Delafontaine who observed it spectroscopically in 1878. Its oxide was first isolated from rare-earth ores by Cleve in 1878.
Hydrogen is the chemical element with the symbol H and atomic number 1\. With a standard atomic weight of , hydrogen is the lightest element in the periodic table. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass.However, most of the universe's mass is not in the form of baryons or chemical elements.
Nuclear fission splits a heavy nucleus such as uranium or plutonium into two lighter nuclei, which are called fission products. Yield refers to the fraction of a fission product produced per fission. Yield can be broken down by: #Individual isotope #Chemical element spanning several isotopes of different mass number but same atomic number. #Nuclei of a given mass number regardless of atomic number.
Dmitri Mendeleev From Boyle until the early 20th century, an element was defined as a pure substance that could not be decomposed into any simpler substance. Put another way, a chemical element cannot be transformed into other chemical elements by chemical processes. Elements during this time were generally distinguished by their atomic weights, a property measurable with fair accuracy by available analytical techniques.
Claude François Geoffroy (1729 - 18 June 1753) was a French chemist. In 1753 he proved the chemical element bismuth to be distinct from lead, becoming the official discoverer of the element. Before this time, bismuth-containing minerals were frequently misidentified as either lead, tin, or antimony ores. His observations on the matter were published in the Mémoires de l’académie française in 1753.
Nascent state or in statu nascendi (Lat. newly formed moiety: in the state of being born or just emerging), is an obsolete theory in chemistry. It refers to the form of a chemical element (or sometimes compound) in the instance of their liberation or formation. Often encountered are atomic oxygen (Onasc), nascent hydrogen (Hnasc), and similar forms of chlorine (Clnasc) or bromine (Brnasc).
Shiva Puja must be performed with linga. The Rasalingam has a place in the worship of Shiva.Parad Shiva lingam Tamil Siddhas identify mercury as Shiva's metal (Shivadhatu). According to Siddha alchemy, mercury is the representation of male (Shiva) form, and the chemical element sulfur associated in the solidification process is considered as the representation of female (Shakti or Gauri, consort of Shiva) form.
An atom is the smallest unit of ordinary matter that forms a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small, typically around 100 picometers across. They are so small that accurately predicting their behavior using classical physics—as if they were tennis balls, for example—is not possible due to quantum effects.
Los is a locality situated in Ljusdal Municipality, Gävleborg County, Sweden with 387 inhabitants in 2010. The village is known for its 18th-century cobalt mine, where Axel Fredrik Cronstedt discovered the chemical element of nickel in 1751. Today, the mine is a tourist attraction. An 8-kilometre-wide crater on Mars was officially named after this village in 1979.
Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most chemicals. The Russian scientist Karl Ernst Claus discovered the element in 1844 and named it after Ruthenia, the Latin word for Rus'.
Rhodium is a chemical element that is a rare, silvery-white, hard, and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope,103Rh. Naturally occurring rhodium is found as the free metal, alloyed with similar metals, and never as a chemical compound.
Xenon is a chemical element with the symbol Xe and atomic number 54. A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts. Although generally unreactive, xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized.—National Standard Reference Data Service of the USSR.
A solar eclipse. Coronium, also called newtonium, was the name of a suggested chemical element, hypothesised in the 19th century. The name, inspired by the solar corona, was given by Gruenwald in 1887. A new atomic thin green line in the solar corona was then considered to be emitted by a new element unlike anything else seen under laboratory conditions.
Neodymium is a chemical element with the symbol Nd and atomic number 60. Neodymium belongs to the lanthanide series and is a rare-earth element. It is a hard, slightly malleable silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly to produce pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states.
Lenin as he appeared in 1887. In 1844, Karl Klaus, a professor at the university, discovered, and named in honour of Russia, Ruthenium, the only chemical element discovered in Tsarist Russia. Six years thereafter St. Petersburg University opened the Institute of Oriental Studies and all training materials and collections of Kazan University in this field were transferred to the capital of Imperial Russia.
The principle behind the use of radioactive tracers is that an atom in a chemical compound is replaced by another atom, of the same chemical element. The substituting atom, however, is a radioactive isotope. This process is often called radioactive labeling. The power of the technique is due to the fact that radioactive decay is much more energetic than chemical reactions.
Krypton (from "the hidden one") is a chemical element with the symbol Kr and atomic number 36\. It is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. With rare exceptions, krypton is chemically inert. Krypton, like the other noble gases, is used in lighting and photography.
Radon is a chemical element with the symbol Rn and atomic number 86\. It is a radioactive, colorless, odorless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into lead and various other short-lived radioactive elements. Radon itself is the immediate decay product of radium.
Nils Gabriel Sefström (2 June 1787 - 30 November 1845) was a Swedish chemist. Sefström was a student of Berzelius and, when studying the brittleness of steel in 1830, he rediscovered a new chemical element, to which he gave the name vanadium. Vanadium was first discovered by the Spanish-Mexican mineralogist Andrés Manuel del Río in 1801. He named it erythronium.
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, it is named after Tantalus, a villain from Greek mythology.Euripides, Orestes Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as minor components in alloys.
Xenon is a chemical element with the symbol Xe and atomic number 54\. It is a colorless, dense, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate, the first noble gas compound to be synthesized.—National Standard Reference Data Service of the USSR.
The Zincke reaction is an organic reaction in which a pyridine is transformed into a pyridinium salt by reaction with 2,4-dinitro-chlorobenzene and a primary amine, named after Theodor Zincke. The Zincke reaction The Zincke reaction should not be confused with the Zincke-Suhl reaction or the Zincke nitration. Furthermore, the Zincke reaction has nothing to do with the chemical element zinc.
Darmstadtium is a chemical element with the symbol Ds and atomic number 110. It is an extremely radioactive synthetic element. The most stable known isotope, darmstadtium-281, has a half-life of approximately 12.7 seconds. Darmstadtium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near the city of Darmstadt, Germany, after which it was named.
The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial.
The Ernest Orlando Lawrence Award was established in his memory in 1959. Chemical element number 103, discovered at the Lawrence Berkeley National Laboratory in 1961, was named lawrencium after him. In 1968 the Lawrence Hall of Science public science education center was established in his honor. His papers are in the Bancroft Library at the University of California in Berkeley.
Standard form of the periodic table of chemical elements. The colors represent different categories of elements A chemical element is a pure substance which is composed of a single type of atom, characterized by its particular number of protons in the nuclei of its atoms, known as the atomic number and represented by the symbol Z. The mass number is the sum of the number of protons and neutrons in a nucleus. Although all the nuclei of all atoms belonging to one element will have the same atomic number, they may not necessarily have the same mass number; atoms of an element which have different mass numbers are known as isotopes. For example, all atoms with 6 protons in their nuclei are atoms of the chemical element carbon, but atoms of carbon may have mass numbers of 12 or 13.
In computer science, B is the symbol for byte, a unit of information storage. In engineering, B is the symbol for bel, a unit of level. In chemistry, B is the symbol for boron, a chemical element. The blood-type B emoji (🅱️) was added in Unicode 6.0 in 2010, and became a popular internet meme in 2018 where letters would be replaced with the emoji.
Explosive antimony is an allotrope of the chemical element antimony that is so sensitive to shocks that it explodes when scratched or subjected to sudden heating. The allotrope was first described in 1855. Chemists form the allotrope through electrolysis of a concentrated solution of antimony trichloride in hydrochloric acid, which forms an amorphous glass. This glass contains significant amounts of halogen impurity at its boundaries.
A systematic element name is the temporary name assigned to a newly synthesized or not yet synthesized chemical element. A systematic symbol is also derived from this name. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as the Transfermium Wars, controversies over the formal name and symbol have been protracted and highly political.
Manganese is a chemical element that is designated by the symbol Mn and has an atomic number of 25. It is found as the free element in nature (often in combination with iron), and in many minerals. The free element is a metal with important industrial metal alloy uses. Manganese ions are variously colored, and are used industrially as pigments and as oxidation chemicals.
Lexicon suggested it should end with the suffix -ium to connote a fundamental ingredient of a computer, like a chemical element. On a list of such names was "Pentium", which stood out to Placek because the prefix pent- could refer to the fifth generation of x86. Lexicon conducted market research and found that consumers would expect a hypothetical "Porsche Pentium" to be Porsche's highest-end car.
The dwarf planet Ceres (discovered 1801), is named after this goddess. And in turn, the chemical element cerium (discovered 1803) was named after the dwarf planet. She is remembered in De Mulieribus Claris, a collection of biographies of historical and mythological women by the Florentine author Giovanni Boccaccio, composed in 136162. It is notable as the first collection devoted exclusively to biographies of women in Western literature.
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with all other elements, except for argon, neon, and helium. Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance.
In some applications, a chemical element is used to combine with the air remaining in an enclosure after pumping. For example, in electronic vacuum tubes, a metallic "getter" was heated by induction to remove the air left after initial pump down and closure of the tubes. The "getter" would also slowly remove any gas evolved within the tube during its remaining life, maintaining sufficiently good vacuum.
An extreme helium star (abbreviated EHe), or a PV Telescopii Variable, is a low-mass supergiant that is almost devoid of hydrogen, the most common chemical element of the Universe. Since there are no known conditions where stars devoid of hydrogen can be formed from molecular clouds, it is theorized that they are the product of the mergers of helium-core and carbon-oxygen core white dwarfs.
The titular protagonist is a fourteen-year-old boy who discovers a previously unknown chemical element. His second novel Itch Rocks was released in February 2013 and the third instalment, Itchcraft, came out in September 2014. His first young adult novel, Blame, was published in July 2016. Mayo's first novel for adults, Mad Blood Stirring, was published in April 2018 and received mixed reviews.
Promethium is a chemical element with the symbol Pm and atomic number 61. All of its isotopes are radioactive; it is extremely rare, with only about 500–600 grams naturally occurring in Earth's crust at any given time. Promethium is one of only two radioactive elements that are followed in the periodic table by elements with stable forms, the other being technetium. Chemically, promethium is a lanthanide.
Chlorine is a component of many other compounds. It is the second most abundant halogen and 21st most abundant chemical element in Earth's crust. The great oxidizing power of chlorine led it to its bleaching and disinfectant uses, as well as being an essential reagent in the chemical industry. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary.
The Lockman Hole is located at about RA 10h 45m, Dec. +58° and is defined by a region of low neutral hydrogen gas and dust column density. Column density is a commonly used measure in astronomy for the quantity of a given chemical element or molecule in a certain direction. In this region, the typical column density of neutral hydrogen is NH = 0.6 x 1020 cm−2.
Europium is a chemical element with the symbol Eu and atomic number 63. Europium is the most reactive lanthanide by far, having to be stored under an inert fluid to protect it from atmospheric oxygen or moisture. Europium is also the softest lanthanide, as it can be dented with a fingernail and easily cut with a knife. When oxidation is removed a shiny-white metal is visible.
Neon discharge tube Neon is the chemical element with atomic number 10, occurring as 20Ne, 21Ne and 22Ne. Neon is a monatomic gas. With a complete octet of outer electrons it is highly resistant to removal of any electron, and it cannot accept an electron from anything. Neon has no tendency to form any normal compounds under normal temperatures and pressures; it is effectively inert.
Hydrogen discharge tube Deuterium discharge tube Hydrogen (H) is the chemical element with atomic number 1. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H2. With an atomic mass of 1.00794 amu, hydrogen is the lightest element. Hydrogen is the most abundant of the chemical elements, constituting roughly 75% of the universe's elemental mass.
Francium and radium make up the s-block elements of the 7th period. Francium is a chemical element with symbol Fr and atomic number 87. It was formerly known as eka-caesium and actinium K.The latter was the name of the most stable isotope, francium-223, which occurs in the actinium series. It is one of the two least electronegative elements, the other being caesium.
Oxygen is the chemical element with atomic number 8, occurring mostly as 16O, but also 17O and 18O. Oxygen is the third-most common element by mass in the universe (although there are more carbon atoms, each carbon atom is lighter). It is highly electronegative and non-metallic, usually diatomic, gas down to very low temperatures. Only fluorine is more reactive among non-metallic elements.
Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus. A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons.
For convenience, three different views of the data are available on Wikipedia: Two sets of “Segmented tables,” and a single “Unitized table (all elements).” The unitized table allows easy visualizion of proton/neutron-count trends but requires simultaneous horizontal and vertical scrolling. The segmented tables permit easier examination of a particular chemical element with much less scrolling. Links are provided to quickly jump between the different sections.
Rubidium is the chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity. Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire.
Titanium is a chemical element with the symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, and high strength. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology.
Kironide is a mineral by which, upon consuming plants containing the mineral, the Platonians (the inhabitants of the planet Platonius) acquire telekinetic powers, including the ability to levitate, in the original series episode "Plato's Stepchildren". Pergium is a substance mined in "The Devil in the Dark", and fictionally given the atomic number 112 as a chemical element in a non-canon Star Trek medical manual publication.
Depiction of a hydrogen atom showing the diameter as about twice the Bohr model radius. (Image not to scale) A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.
Binary compounds of hydrogen are binary chemical compounds containing just hydrogen and one other chemical element. By convention all binary hydrogen compounds are called hydrides even when the hydrogen atom in it is not an anion.Concise Inorganic Chemistry J.D. LeeMain Group Chemistry, 2nd Edition, A. G. MasseyAdvanced Inorganic Chemistry F. Albert Cotton, Geoffrey WilkinsonInorganic chemistry, Catherine E. Housecroft, A. G. Sharpe These hydrogen compounds can be grouped into several types.
The street in front of these is named after him as Mendeleevskaya liniya (Mendeleev Line). In Moscow, there is the D. Mendeleyev University of Chemical Technology of Russia. After him was also named mendelevium, which is a synthetic chemical element with the symbol Md (formerly Mv) and the atomic number 101. It is a metallic radioactive transuranic element in the actinide series, usually synthesized by bombarding einsteinium with alpha particles.
His name is based on Sulfur, a type of chemical element. ; :Voiced by: Hiroshi Shimozaki Moldavite is the Headmaster of the Magic Academy, where the Jewelpets attend to learn about magic. He's also Rin's partner in Jewelpet Twinkle and has a close relation with Jewelina. Although he retains his position as Headmaster, he's very jolly, likes karaoke and orders a lot of magic stuff through the magical mail order.
Gallium is a chemical element with the symbol Ga and atomic number 31\. Elemental gallium is a soft, silvery metal at standard temperature and pressure; however in its liquid state it becomes silvery white. If too much force is applied, the gallium may fracture conchoidally. It is in group 13 of the periodic table, and thus has similarities to the other metals of the group, aluminium, indium, and thallium.
Gold is a chemical element with the symbol Au (from ) and atomic number 79, making it one of the higher atomic number elements that occur naturally. In a pure form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions.
The town was named after valuable ore compounds of the chemical element tellurium, a metalloid element which forms natural tellurides, the most notable of which are telluride ores of gold and silver. Although gold telluride minerals were never actually found in the mountains near Telluride, the area's mines were rich in zinc, lead, copper, silver, and ores which contained gold in other forms. Telluride began slowly because of its isolated location.
Lutetium is a chemical element with the symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earths. Lutetium is sometimes considered the first element of the 6th-period transition metals, although lanthanum is more often considered as such.
According to IUPAC, chemical elements are not proper nouns in English; consequently, the full name of an element is not routinely capitalized in English, even if derived from a proper noun, as in californium and einsteinium. Isotope names of chemical elements are also uncapitalized if written out, e.g., carbon-12 or uranium-235. Chemical element symbols (such as Cf for californium and Es for einsteinium), are always capitalized (see below).
Because of its great reactivity, all chlorine in the Earth's crust is in the form of ionic chloride compounds, which includes table salt. It is the second-most abundant halogen (after fluorine) and twenty-first most abundant chemical element in Earth's crust. These crustal deposits are nevertheless dwarfed by the huge reserves of chloride in seawater. Elemental chlorine is commercially produced from brine by electrolysis, predominantly in the chlor-alkali process.
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide- nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust and the third most abundant metal, after iron and aluminium.
Potassium is a chemical element with the symbol K (from Neo-Latin kalium) and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives.
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Earth. It has a concentration in the Earth's crust of about one gram per kilogram (compare copper at about 0.06 grams). In minerals, phosphorus generally occurs as phosphate.
Actinium is a chemical element with the symbol Ac and atomic number 89\. It was first isolated by French chemist André-Louis Debierne in 1899. Friedrich Oskar Giesel later independently isolated it in 1902 and, unaware that it was already known, gave it the name emanium. Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table.
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars, beryllium is depleted as it is fused into heavier elements. It is a divalent element which occurs naturally only in combination with other elements in minerals.
Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and it has often been classified as a "rare earth element". Yttrium is almost always found combined with the lanthanides in rare earth minerals and is never found in nature as a free element. Its only stable isotope, 89Y, is also its only naturally occurring isotope.
Niobium, or columbium, is a chemical element with the symbol Nb and atomic number 41. It is a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite. The name comes from Greek mythology: Niobe, daughter of Tantalus. Niobium has physical and chemical properties similar to those of the element tantalum, and the two are therefore difficult to distinguish.
Boron is a chemical element with the symbol B and atomic number 5\. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar System and in the Earth's crust. It constitutes about 0.001 percent by weight of Earth's crust. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals.
Helvetium was the suggested name of chemical element number 85, now known as astatine, given to it by the Swiss chemist Walter Minder. Walter Minder announced the discovery in 1940. He chose the name based on "Helvetia", the Latin name for Switzerland, to honor his country of birth. In the year 1942 he together with Alice Leigh-Smith announced a second time the discovery of element number 85.
Diamond and graphite, two different allotropes of carbon Carbon is the chemical element with atomic number 6, occurring as 12C, 13C and 14C.Carbon at WebElements. At standard temperature and pressure, carbon is a solid, occurring in many different allotropes, the most common of which are graphite, diamond, the fullerenes and amorphous carbon. Graphite is a soft, hexagonal crystalline, opaque black semimetal with very good conductive and thermodynamically stable properties.
Magnesium (Mg) is a chemical element, an alkaline earth metal, the eighth-most abundant element in the Earth's crust and the fourth-most common element on Earth. It is contained in magnesite, dolomite, brucite, carnallite, talc, and magnesium minerals. China is now the biggest producer of crude magnesite in the world for refractory and agricultural uses. Magnesite quarries in Gerakini, Chalkidiki Crude magnesite was produced in Greece in 1910.
Niobium, also known as columbium, is a chemical element with the symbol Nb (formerly Cb) and atomic number 41. Niobium is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to that of pure titanium, and it has similar ductility to iron. Niobium oxidizes in the earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel.
Nobelium is a synthetic chemical element with the symbol No and atomic number 102. It is named in honor of Alfred Nobel, the inventor of dynamite and benefactor of science. A radioactive metal, it is the tenth transuranic element and is the penultimate member of the actinide series. Like all elements with atomic number over 100, nobelium can only be produced in particle accelerators by bombarding lighter elements with charged particles.
Wasium was the suggested name of chemical element found J. F. Bahr. The name derived from the House of Vasa the Royal House of Sweden. In 1862 Bahr analysed the mineral Orthite—Allanite-(Y)—from the Norwegian island Rönsholm and found an oxide which he concluded contained a new element. In the following years several articles were published making clear that the wasium oxide was a mixture of several other elements.
Isotopes are variants of a particular chemical element which differ in neutron number. All isotopes of a given element have the same number of protons in each atom. The term isotope is formed from the Greek roots isos (ἴσος "equal") and topos (τόπος "place"), meaning "the same place"; thus, the meaning behind the name is that different isotopes of a single element occupy the same position on the periodic table.
Berkelium is a transuranic radioactive chemical element with the symbol Bk and atomic number 97. It is a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the Lawrence Berkeley National Laboratory (then the University of California Radiation Laboratory) where it was discovered in December 1949. Berkelium was the fifth transuranium element discovered after neptunium, plutonium, curium and americium.
Barium is a chemical element with the symbol Ba and atomic number 56\. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are barite (now called baryte) (barium sulfate, BaSO4) and witherite (barium carbonate, BaCO3), both insoluble in water.
Tin is a chemical element with the symbol Sn (from ) and atomic number 50\. Tin is a silvery metal that characteristically has a faint yellow hue. Tin, like indium, is soft enough to be cut without much force. When a bar of tin is bent, the so-called “tin cry” can be heard as a result of twinning in tin crystals; this trait is shared by indium, cadmium, and frozen mercury.
GEOTRACES is an international research programme that aims to improve an understanding of biogeochemical cycles in the oceans. The concept of cycle describes the pathway by which a chemical element moves through the three major compartments of Earth (such as continents, atmosphere, and ocean). Because these cycles are directly related to climate dynamics and are heavily impacted by global change, it is essential to quantify them.Chemical & Engineering News Vol.
This cursive 'w' was popular in calligraphy of the eighteenth century; a late appearance in a font of c. 1816. W is the symbol for the chemical element tungsten, after its German (and alternative English) name, Wolfram. It is also the SI symbol for the watt, the standard unit of power. It is also often used as a variable in mathematics, especially to represent a complex number or a vector.
In 1851 Lassell eventually numbered all four known satellites in order of their distance from the planet by Roman numerals, and since then Titania has been designated '. Shakespeare's character's name is pronounced , but the moon is often pronounced , by analogy with the familiar chemical element titanium. The adjectival form, Titanian, is homonymous with that of Saturn's moon Titan. The name Titania is ancient Greek in origin, meaning "Daughter of the Titans".
Argon's name is taken from the colourless chemical element Argon, meaning that the group is "not limited to a single color" and they can "absorb multiple genres". The name is also an acronym for "Art Go On", meaning that "art continues". Argon released their first single album, Master Key, through various platforms on March 11, 2019. They held their debut showcase at the Ilji Art Hall in Gangnam the same day.
Iron () is a chemical element with symbol Fe (from ) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is by mass the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust.
The name Rare isotope Accelerator complex for ON-line experiment or RAON, was selected through a contest open to the public in 2012. RAON comes from the Korean word meaning "happy" or "joyful". Among 639 entries, the winning name was actually Raonhaje (라온하제) meaning "happy tomorrow" but was shortened for easier pronunciation. RAON is also the name of their chemical element mascot with atomic number 41 and niobium written on the stomach.
Francium is a chemical element with the symbol Fr and atomic number 87\. Prior to its discovery, it was referred to as eka-caesium. It is extremely radioactive; its most stable isotope, francium-223 (originally called actinium K after the natural decay chain it appears in), has a half-life of only 22 minutes. It is the second-most electropositive element, behind only caesium, and is the second rarest naturally occurring element (after astatine).
Oganesson is a synthetic chemical element with the symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow, Russia, by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new elements by the Joint Working Party of the international scientific bodies IUPAC and IUPAP. It was formally named on 28 November 2016.
Curium is a transuranic radioactive chemical element with the symbol Cm and atomic number 96. This element of the actinide series was named after Marie and Pierre Curie, both known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley. The discovery was kept secret and only released to the public in November 1947.
For example, in varying the assumed abundance of a chemical element, and comparing the synthetic spectra to observed ones, the abundance of that element in that particular star can be determined. As computers have evolved, the complexity of the models has deepened, becoming more realistic in including more physical data and excluding more of the simplifying assumptions. This evolution of the models has also made them applicable to different kinds of stars.
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Coster and Hevesy, making it the last stable element to be discovered. Hafnium is named after Hafnia, the Latin name for Copenhagen, where it was discovered.
In 1922 de Hevesy co-discovered (with Dirk Coster) the element hafnium (72Hf) (Latin Hafnia for "Copenhagen", the home town of Niels Bohr). Mendeleev's 1869 periodic table arranged the chemical elements into a logical system, but a chemical element with 72 protons was missing. Hevesy determined to look for that element on the basis of Bohr's atomic model. The mineralogical museum of Norway and Greenland in Copenhagen furnished the material for the research.
The theory is very complicated but, in essence, the radioactive elements within an object decay to form isotopes of each chemical element. Isotopes are atoms of the element that differ in mass but share the same general properties. Geologists are most interested in the decay of isotopes carbon-14 (into nitrogen-14) and potassium-40 (into argon-40). Carbon-14 aka radiocarbon dating works for organic materials that are less than about 50,000 years old.
Only a few houses remained standing. The surviving inhabitants fled behind the walls of the city of Darmstadt, where many of them died of the plague. By the end of the war in 1648 only about 12 families were left, who set out to rebuild the community. The chemical element Darmstadtium (atomic number 110) is named after Darmstadt, having been synthetisized in the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt-Arheilgen.
Copper is a chemical element with the symbol Cu (from Latin: cuprum) and the atomic number of 29. It is easily recognisable, due to its distinct red-orange color. Copper also has a range of different organic and inorganic salts, having varying oxidation states ranging from (0,I) to (III). These salts (mostly the (II) salts) are often blue to green in color, rather than the orange color copper is known for.
Aluminium-26 (26Al, Al-26) is a radioactive isotope of the chemical element aluminium, decaying by either positron emission or electron capture to stable magnesium-26. The half-life of 26Al is 7.17 years. This is far too short for the isotope to survive as a primordial nuclide, but a small amount of it is produced by collisions of atoms with cosmic ray protons. Decay of aluminium-26 also produces gamma rays and x-rays.
Carbene analogs in chemistry are carbenes with the carbon atom replaced by another chemical element. Just as regular carbenes they appear in chemical reactions as reactive intermediates and with special precautions they can be stabilized and isolated as chemical compounds. Carbenes have some practical utility in organic synthesis but carbene analogs are mostly laboratory curiosities only investigated in academia. Carbene analogs are known for elements of group 13, group 14, group 15 and group 16.
The absorption neutron cross section of an isotope of a chemical element is the effective cross sectional area that an atom of that isotope presents to absorption, and is a measure of the probability of neutron capture. It is usually measured in barns (b). Absorption cross section is often highly dependent on neutron energy. As a generality, the likelihood of absorption is proportional to the time the neutron is in the vicinity of the nucleus.
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals. There is neither a standard definition of a metalloid nor complete agreement on the elements appropriately classified as such. Despite the lack of specificity, the term remains in use in the literature of chemistry. The six commonly recognised metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.
Glenn Seaborg told his students that he proposed the chemical symbol Pu (from P U) instead of the conventional "Pl" for plutonium as a joke, only to find it officially adopted.Glenn T. Seaborg, Citizen-Scholar, By Peggy House, Reprinted from The Seaborg Center Bulletin, April 1999 Unununium (Uuu) was the former temporary name of the chemical element number 111, a synthetic transuranium element. This element was named roentgenium (Rg) in November 2004.
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13\. It is a silvery-white, soft, non- magnetic and ductile metal in the boron group. By mass, aluminium is the most abundant metal in the Earth's crust and the third most abundant element (after oxygen and silicon). The abundance of aluminium decreases relative to other elements at greater depths into Earth's mantle and beyond.
Additions of various Lewis acids to pyridine Lewis acids easily add to the nitrogen atom of pyridine, forming pyridinium salts. The reaction with alkyl halides leads to alkylation of the nitrogen atom. This creates a positive charge in the ring that increases the reactivity of pyridine to both oxidation and reduction. The Zincke reaction is used for the selective introduction of radicals in pyridinium compounds (it has no relation to the chemical element zinc).
Crystal structure of I-CreI bound to its DNA recognition sequence. The enzyme binds as a homodimer; one subunit is depicted in yellow, the other in pink. The enzyme is shown in surface representation; DNA molecule is shown as a collection of spheres, each colored according to its chemical element. The homing endonucleases are a collection of endonucleases encoded either as freestanding genes within introns, as fusions with host proteins, or as self- splicing inteins.
Yttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals, and is never found in nature as a free element. 89Y is the only stable isotope, and the only isotope found in the Earth's crust.
Liquid nitrogen being poured Nitrogen is the chemical element with atomic number 7, the symbol N and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772. It occurs naturally in form of two isotopes: nitrogen-14 and nitrogen-15.
Liquid fluorine in ampoule Fluorine is the chemical element with atomic number 9. It occurs naturally in its only stable form 19F. Fluorine is a pale-yellow, diatomic gas under normal conditions and down to very low temperatures. Short one electron of the highly stable octet in each atom, fluorine molecules are unstable enough that they easily snap, with loose fluorine atoms tending to grab single electrons from just about any other element.
In chemistry, an alkali (; from al-qaly "ashes of the saltwort") is a basic, ionic salt of an alkali metal or alkaline earth metal chemical element. An alkali also can be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline is commonly, and alkalescent less often, used in English as a synonym for basic, especially for bases soluble in water.
The nuclei of the heavy hydrogen isotopes deuterium (D or 2H) and tritium (T or 3H) contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons. The most common nuclide of the common chemical element lead, 208Pb, has 82 protons and 126 neutrons, for example. The table of nuclides comprises all the known nuclides.
Nickel is a chemical element with the symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile. Pure nickel, powdered to maximize the reactive surface area, shows a significant chemical activity, but larger pieces are slow to react with air under standard conditions because an oxide layer forms on the surface and prevents further corrosion (passivation).
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately hard, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. All known thorium isotopes are unstable.
Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive, none of which is stable other than the fully ionized state of 97Tc. Nearly all available technetium is produced as a synthetic element. Naturally occurring technetium is a spontaneous fission product in uranium ore and thorium ore, the most common source, or the product of neutron capture in molybdenum ores.
After numerous laborious purifications, Bunsen proved that highly pure samples gave unique spectra. In the course of this work, Bunsen detected previously unknown new blue spectral emission lines in samples of mineral water from Dürkheim. He guessed that these lines indicated the existence of an undiscovered chemical element. After careful distillation of forty tons of this water, in the spring of 1860 he was able to isolate 17 grams of a new element.
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation. Andrés Manuel del Río discovered compounds of vanadium in 1801 in Mexico by analyzing a new lead-bearing mineral he called "brown lead".
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a blue-silvery appearance when oxidation is removed. It is the first element in group 12 of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.
Ytterbium is a chemical element with the symbol Yb and atomic number 70\. It is the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. However, like the other lanthanides, its most common oxidation state is +3, as in its oxide, halides, and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble ytterbium compounds form complexes with nine water molecules.
Flerovium is a superheavy artificial chemical element with the symbol Fl and atomic number 114. It is an extremely radioactive synthetic element. The element is named after the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research in Dubna, Russia, where the element was discovered in 1998. The name of the laboratory, in turn, honours the Russian physicist Georgy Flyorov ( in Cyrillic, hence the transliteration of "yo" to "e").
He was appointed lecturer in chemistry at the University of Glasgow in 1787, and professor of medicine in 1789. In January 1788, on the proposal of John Walker, Daniel Rutherford and Alexander Monro, he was elected a Fellow of the Royal Society of Edinburgh. In 1791-2 Hope completed experiments on the chemical element strontium, proposing the name Stronities for it, after Strontian, the west highland village where he found strontianite. The element was later renamed to Strontium.
Praseodymium is a chemical element with the symbol Pr and atomic number 59. It is the third member of the lanthanide series and is traditionally considered to be one of the rare-earth metals. Praseodymium is a soft, silvery, malleable and ductile metal, valued for its magnetic, electrical, chemical, and optical properties. It is too reactive to be found in native form, and pure praseodymium metal slowly develops a green oxide coating when exposed to air.
Tennessine is a synthetic chemical element with the symbol Ts and atomic number 117. It is the second-heaviest known element and the penultimate element of the 7th period of the periodic table. The discovery of tennessine was officially announced in Dubna, Russia, by a Russian–American collaboration in April 2010, which makes it the most recently discovered element . One of its daughter isotopes was created directly in 2011, partially confirming the results of the experiment.
Manganese is a chemical element with the symbol Mn and atomic number 25. It is not found as a free element in nature; it is often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. Historically, manganese is named for pyrolusite and other black minerals from the region of Magnesia in Greece, which also gave its name to magnesium and the iron ore magnetite.
Caesium (IUPAC spelling) (also spelled cesium in American English) is a chemical element with the symbol Cs and atomic number 55\. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. The most reactive of all metals, it is pyrophoric and reacts with water even at .
Carbon films are thin film coatings which consist predominantly of the chemical element carbon. They include plasma polymer films, amorphous carbon films (diamond-like carbon, DLC), CVD diamond films as well as graphite films. Carbon films are produced by deposition using gas-phase deposition processes in most cases taking place in a vacuum: chemical vapor deposition, CVD or physical vapor deposition, PVD. They are deposited in the form of thin films with film thicknesses of just a few micrometres.
In 2013 the Canadian mining company Minco sank deep boreholes in an effort to discover the extent of zinc deposits beneath Nenthead. Although test drilling could go on for several years, the company believes that the village may be sited on huge deposits of the chemical element. The zinc is below the surface and was previously too deep to reach by old mining techniques. The Independent (Accessed 12 January 2014) Gives details of possible zinc deposits.
Pu-239 is a 2006 film directed by Hollywood producer Scott Z. Burns based on the book PU-239 and Other Russian Fantasies written by Ken Kalfus. The film was shown twice at the 2006 Toronto International Film Festival under the title The Half Life of Timofey Berezin before being distributed by HBO Films under its original working title. Pu-239 is the chemical symbol for plutonium-239 (239Pu), a radioactive isotope of the chemical element plutonium.
Field repressurization began in 1944 and water flooding started in 1948." "Only months after Union Gas completed a scrubbing facility for its Tilbury gas in Ontario, in 1924 Royalite began sweetening gas from the sour Royalite #4 well through a similar plant. This process removed H2S from the gas, but did not extract the sulfur as a chemical element. This development waited until 1952, when a sulfur recovery plant at Turner Valley began producing raw sulfur.
Livermore was founded by William Mendenhall and named for Robert Livermore, his friend and a local rancher who settled in the area in the 1840s. Livermore is the home of the Lawrence Livermore National Laboratory, for which the chemical element livermorium is named (and thus, placing the city's name in the periodic table). Livermore is also the California site of Sandia National Laboratories, which is headquartered in Albuquerque, New Mexico. Its south side is home to local vineyards.
The mineral group tantalite [(Fe, Mn)Ta2O6] is the primary source of the chemical element tantalum. It is chemically similar to columbite, and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides. However, tantalite has a much greater specific gravity than columbite (8.0+ compared to columbite's 5.2). Iron-rich tantalite is the mineral tantalite-(Fe) or ferrotantalite and manganese-rich is tantalite-(Mn) or manganotantalite.
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs).
Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own radioactivity.
Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature. Naturally occurring technetium occurs as a spontaneous fission product in uranium ore or by neutron capture in molybdenum ores. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese.
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs).
Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible other metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two. Indium was discovered in 1863 and named for the indigo blue line in its spectrum that was the first indication of its existence in zinc ores, as a new and unknown element. The metal was first isolated in the following year.
Tin is a chemical element with the symbol Sn (for ) and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead and has two possible oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table.
Antimony () is a toxic chemical element with the symbol Sb and an atomic number of 51. A lustrous grey metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were used for cosmetics, metallic antimony was also known but mostly identified as lead. For some time China has been the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan.
Large piece of beryllium Beryllium (Be) is the chemical element with atomic number 4, occurring in the form of 9Be. At standard temperature and pressure, beryllium is a strong, steel-grey, light-weight, brittle, bivalent alkali earth metal, with a density of 1.85 g⋅cm−3.Beryllium at WebElements. It also has one of the highest melting points of all the light metals. Beryllium's most common isotope is 9Be, which contains 4 protons and 5 neutrons.
Dalton proposed that each chemical element is composed of atoms of a single, unique type, and though they cannot be altered or destroyed by chemical means, they can combine to form more complex structures (chemical compounds). This marked the first truly scientific theory of the atom, since Dalton reached his conclusions by experimentation and examination of the results in an empirical fashion. Various atoms and molecules as depicted in John Dalton's A New System of Chemical Philosophy (1808).
Rutherfordium is a synthetic chemical element with the symbol Rf and atomic number 104, named after New Zealand physicist Ernest Rutherford. As a synthetic element, it is not found in nature and can only be created in a laboratory. It is radioactive; the most stable known isotope, 267Rf, has a half-life of approximately 1.3 hours. In the periodic table of the elements, it is a d-block element and the second of the fourth-row transition elements.
Ruthenium is a chemical element with the symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Russian-born scientist of Baltic-German ancestry Karl Ernst Claus discovered the element in 1844 at Kazan State University and named ruthenium in honor of Ruthenia (one of Medieval Latin names for Russia).
Meitnerium is a synthetic chemical element with the symbol Mt and atomic number 109. It is an extremely radioactive synthetic element (an element not found in nature, but can be created in a laboratory). The most stable known isotope, meitnerium-278, has a half-life of 4.5 seconds, although the unconfirmed meitnerium-282 may have a longer half-life of 67 seconds. The GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany, first created this element in 1982.
Erbium is a chemical element with the symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare earth element, originally found in the gadolinite mine in Ytterby in Sweden, from which it got its name. Erbium's principal uses involve its pink-colored Er3+ ions, which have optical fluorescent properties particularly useful in certain laser applications.
Terbium is a chemical element with the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife. The ninth member of the lanthanide series, terbium is a fairly electropositive metal that reacts with water, evolving hydrogen gas. Terbium is never found in nature as a free element, but it is contained in many minerals, including cerite, gadolinite, monazite, xenotime, and euxenite.
Proton-rich nuclides can be produced by sequentially adding one or more protons to an atomic nucleus. Such a nuclear reaction of type (p,γ) is called proton capture reaction. By adding a proton to a nucleus, the element is changed because the chemical element is defined by the proton number of a nucleus. At the same time the ratio of protons to neutrons is changed, resulting in a more neutron-deficient isotope of the next element.
Swedish: Nya Bastnässtollen Bastnäs ( or ) is an ore field near Riddarhyttan, Västmanland, Sweden. The mines in Bastnäs were earliest mentioned in 1692. Iron, copper and rare-earth elements were extracted from the mines and 4,500 tons of cerium was produced between 1875 and 1888. The chemical element cerium was first discovered in Bastnäs in 1803 by Jöns Jakob Berzelius and Wilhelm Hisinger in the form of its oxide, ceria, and independently in Germany by Martin Heinrich Klaproth.
The three naturally-occurring isotopes of hydrogen. The fact that each isotope has one proton makes them all variants of hydrogen: the identity of the isotope is given by the number of protons and neutrons. From left to right, the isotopes are protium (1H) with zero neutrons, deuterium (2H) with one neutron, and tritium (3H) with two neutrons. Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.
Liquid helium is a physical state of helium, at very low temperatures if it is at standard atmospheric pressures. Liquid helium may show superfluidity. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (about 4 K or −452.2 °F). Its boiling point and critical point depend on which isotope of helium is present: the common isotope helium-4 or the rare isotope helium-3.
Stable isotope fractionation is a useful way of characterising organic carbon and inorganic carbon. These numbers are reported as values, where C is for the chemical element carbon. Isotope analysis of inorganic carbon typically yields δ13C values heavier than −10 per mil, with numbers usually falling between −5 and 5 per mil. Organic carbon, however, has δ13C values that range from −20 per mil for photoautotrophic bacteria to −60 per mil for microbial communities that recycle methane.
Bohrium is a synthetic chemical element with the symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in a laboratory but is not found in nature. All known isotopes of bohrium are extremely radioactive; the most stable known isotope is 270Bh with a half-life of approximately 61 seconds, though the unconfirmed 278Bh may have a longer half-life of about 690 seconds.
In 1794, after careful chemical analysis, Gadolin reported that approximately 38% of the sample was a previously unknown "earth". (The idea of chemical element was not yet established.) The compound that Gadolin isolated, the first rare-earth metal compound, is now known as Yttrium(III) oxide. It is composed of the first known rare-earth element, yttrium. Examining a different sample, Anders Gustaf Ekeberg confirmed the existence of a new "earth", calling it "yttria" and the source mineral "ytterbite".
Hassium is a chemical element with the symbol Hs and the atomic number 108. Hassium is highly radioactive; its most stable known isotopes have half-lives of approximately ten seconds. One of its isotopes, 270Hs, has magic numbers of both protons and neutrons for deformed nuclei, which gives it greater stability against spontaneous fission. Hassium is a superheavy element; it has been produced in a laboratory only in very small quantities by fusing heavy nuclei with lighter ones.
When the alloys for piping are forged, metallurgical tests are performed to determine material composition by % of each chemical element in the piping, and the results are recorded in a Material Test Report (MTR). These tests can be used to prove that the alloy conforms to various specifications (e.g. 316 SS). The tests are stamped by the mill's QA/QC department and can be used to trace the material back to the mill by future users, such as piping and fitting manufacturers.
Moscovium is a synthetic chemical element with the symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. In December 2015, it was recognized as one of four new elements by the Joint Working Party of international scientific bodies IUPAC and IUPAP. On 28 November 2016, it was officially named after the Moscow Oblast, in which the JINR is situated.
Molybdenum is a chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin molybdaenum, which is based on Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm.
As a result, even if the indigenous medical knowledge is taken as prior art, that knowledge does not by itself make the active chemical compound "obvious," which is the standard applied under patent law. In the United States, patent law can be used to protect "isolated and purified" compounds – even, in one instance, a new chemical element (see USP 3,156,523). In 1873, Louis Pasteur patented a "yeast" which was "free from disease" (patent #141072). Patents covering biological inventions have been treated similarly.
In astrology, the planet Uranus (22px) is the ruling planet of Aquarius. Because Uranus is cyan and Uranus is associated with electricity, the colour electric blue, which is close to cyan, is associated with the sign Aquarius (see Uranus in astrology). The chemical element uranium, discovered in 1789 by the German chemist Martin Heinrich Klaproth, was named after the then-newly discovered Uranus. "Uranus, the Magician" is a movement in Gustav Holst's orchestral suite The Planets, written between 1914 and 1916.
The first systematic and widespread use of medial capitals for technical purposes was the notation for chemical formulae invented by the Swedish chemist Jacob Berzelius in 1813. To replace the multitude of naming and symbol conventions used by chemists until that time, he proposed to indicate each chemical element by a symbol of one or two letters, the first one being capitalized. The capitalization allowed formulae like "NaCl" to be written without spaces and still be parsed without ambiguity.Jöns Jacob Berzelius (1813).
Lawrencium is a synthetic chemical element with the symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles.
Roentgenium is a chemical element with the symbol Rg and atomic number 111. It is an extremely radioactive synthetic element that can be created in a laboratory but is not found in nature. The most stable known isotope, roentgenium-282, has a half-life of 100 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany.
After sharing the 1951 Nobel Prize in Chemistry with Edwin McMillan, he received approximately 50 honorary doctorates and numerous other awards and honors. The list of things named after Seaborg ranges from the chemical element seaborgium to the asteroid 4856 Seaborg. He was a prolific author, penning numerous books and 500 journal articles, often in collaboration with others. He was once listed in the Guinness Book of World Records as the person with the longest entry in Who's Who in America.
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the Pauling scale, behind only oxygen and fluorine.
All atoms bigger than hydrogen are formed in stars or supernovae through nucleosynthesis, when gravity, temperature and pressure reach levels high enough to fuse protons and neutrons together. Protons and neutrons form the atomic nucleus, which accumulates electrons to form atoms. The number of protons in the nucleus, called atomic number, uniquely identifies a chemical element. The Oddo–Harkins rule argues that elements with odd atomic numbers have one unpaired proton and are more likely to capture another, thus increasing their atomic number.
Soon after the Big Bang, which occurred roughly 14 Gya, the only chemical elements present in the universe were hydrogen, helium, and lithium, the three lightest atoms in the periodic table. These elements gradually came together to form stars. These early stars were massive and short-lived, producing heavier elements through stellar nucleosynthesis. Carbon, currently the fourth most abundant chemical element in the universe (after hydrogen, helium and oxygen), was formed mainly in white dwarf stars, particularly those bigger than two solar masses.
Tantalum's heavier analogue was later found to be the transuranic element dubnium – which, however, does not react like tantalum, but like protactinium. In 1900, William Crookes isolated protactinium as an intensely radioactive material from uranium; however, he could not characterize it as a new chemical element and thus named it uranium-X (UX). Crookes dissolved uranium nitrate in ether, and the residual aqueous phase contains most of the and . His method was still used in the 1950s to isolate and from uranium compounds.
On December 21, 1898, the Curies detected the presence of another radioactive material in the pitchblende. They presented this finding to the French Academy of Sciences on December 26, proposing that the new element be called radium. The Curies then went to work isolating polonium and radium from naturally occurring compounds to prove that they were new elements. In 1902, the Curies announced that they had produced a decigram of pure radium, demonstrating its existence as a unique chemical element.
Patrick Maynard Stuart Blackett, Baron Blackett (18 November 1897 – 13 July 1974) was a British experimental physicist known for his work on cloud chambers, cosmic rays, and paleomagnetism, winning the Nobel Prize for Physics in 1948. In 1925 he became the first person to prove that radioactivity could cause the nuclear transmutation of one chemical element to another.Blackett, Patrick Maynard Stewart (2 Feb. 1925) "The Ejection of Protons From Nitrogen Nuclei, Photographed by the Wilson Method," Journal of the Chemical Society Transactions.
Antimony is a chemical element with the symbol Sb (from ) and atomic number 51\. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl.David Kimhi's Commentary on Jeremiah 4:30 and I Chronicles 29:2; Hebrew: פוך/כְּחֻל, Aramaic: כּוּחְלִי/צדידא; Arabic: كحل, and which can also refer to antimony trisulfide.
Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. Cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements.
Molybdenum is a Group 6 chemical element with the symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek , meaning lead, itself proposed as a loanword from Anatolian Luvian and Lydian languages, since its ores were confused with lead ores. The free element, which is a silvery metal, has the sixth-highest melting point of any element. It readily forms hard, stable carbides, and for this reason it is often used in high-strength steel alloys.
Johan Gadolin (5 June 176015 August 1852) was a Finnish chemist, physicist and mineralogist. Gadolin discovered a "new earth" containing the first rare-earth compound yttrium, which was later determined to be a chemical element. He is also considered the founder of Finnish chemistry research, as the second holder of the Chair of Chemistry at the Royal Academy of Turku (or Åbo Kungliga Akademi). Gadolin was ennobled for his achievements and awarded the Order of Saint Vladimir and the Order of Saint Anna.
The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, set by the number of protons, or atomic number. Neutrons do not affect the electron configuration, but the sum of atomic number and the number of neutrons, or neutron number, is the mass of the nucleus. Atoms of a chemical element that differ only in neutron number are called isotopes.
Nitrogen is the chemical element with the symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772. Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. The name nitrogène was suggested by French chemist Jean-Antoine-Claude Chaptal in 1790 when it was found that nitrogen was present in nitric acid and nitrates.
She named the first chemical element she discovered polonium, after her native country. Marie Curie died in 1934, aged 66, at a sanatorium in Sancellemoz (Haute-Savoie), France, of aplastic anaemia from exposure to radiation in the course of her scientific research and in the course of her radiological work at field hospitals during World War I. (a 2013 BBC documentary) In 1995, she became the first woman to be entombed on her own merits in the Panthéon in Paris.
Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek βρῶμος ("stench"), referencing its sharp and disagreeable smell.
Some oil shales are suitable source for sulfur, ammonia, alumina, soda ash, and nahcolite which occur as shale oil extraction byproducts. Some oil shales can also be used for uranium and other rare chemical element production. During 1946-1952, a marine variety of Dictyonema shale was used for uranium production in Sillamäe, Estonia, and during 1950-1989 alum shale was used in Sweden for the same purpose. Oil shale gas can also be used as a substitute for natural gas.
Xylylene dichloride can be artificially synthesized with a Chinese invention which relates to a 1,4-bis(chloromethyl)benzene synthesis technology. In this technology, the aromatic hydrocarbon p-xylene and the chemical element chlorine react with an ionic liquid catalyst under LED light source to form a 1,4-bis(chloromethyl)benzene reaction solution. After that, the solution is cooled and separated, so that a crude product is obtained. 1,4-bis(chloromethyl)benzene is obtained by vacuum rectification of the crude product.
A Grotrian diagram of doubly ionized oxygen: forbidden transitions in the visible spectrum are shown in green. In astronomy and atomic physics, doubly ionized oxygen is the ion O2+ (also known as O III in spectroscopic notation). Its emission forbidden lines in the visible spectrum fall primarily at the wavelength 500.7 nm, and secondarily at 495.9 nm. Before spectra of oxygen ions became known, these lines once led to a spurious identification of the substance as a new chemical element.
A molecule may be homonuclear, that is, it consists of atoms of one chemical element, as with two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, as with water (two hydrogen atoms and one oxygen atom; H2O). Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not considered single molecules. Molecules as components of matter are common. They also make up most of the oceans and atmosphere.
Some, such as the Andromeda Nebula, had spectra quite similar to those of stars, but turned out to be galaxies consisting of hundreds of millions of individual stars. Others looked very different. Rather than a strong continuum with absorption lines superimposed, the Orion Nebula and other similar objects showed only a small number of emission lines. In planetary nebulae, the brightest of these spectral lines was at a wavelength of 500.7 nanometres, which did not correspond with a line of any known chemical element.
The name xenotime is from the Greek words κενός vain and τιμή honor, akin to "vainglory". It was coined by French mineralogist François Sulpice Beudant as a rebuke of another scientist, Swedish chemist Jöns Jacob Berzelius, for the latter's premature claim to have found in the mineral a new chemical element (later understood to be previously discovered yttrium). The criticism was blunted, as over time "kenotime" was misread and misprinted "xenotime". Xenotime was first described for an occurrence in Vest-Agder, Norway in 1824.
Ununennium, also known as eka-francium or element 119, is the hypothetical chemical element with symbol Uue and atomic number 119. Ununennium and Uue are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be an s-block element, an alkali metal, and the first element in the eighth period. It is the lightest element that has not yet been synthesized.
The establishment of the society was followed by the founding of the Seminar of Vergara a decade later (1776), the first higher education institution to operate in Basque territory. Research carried out by Fausto Elhuyar and brother Juan Jose in the seminar led to their isolating of the chemical element tungsten, and Ignacio de Zavala came up with the procedure to obtain cast steel. In music the Society sponsored the work of composer José de Larrañaga. Literary activity was conducted by Félix María de Samaniego and others.
Diagram of a helium atom, showing the electron probability density as shades of gray. The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius.
This new, heavier isotope may be either stable or unstable (radioactive), depending on the chemical element involved. Because free neutrons disintegrate within minutes outside of an atomic nucleus, free neutrons can be obtained only from nuclear decay, nuclear reaction, and high- energy interaction, such as cosmic radiation or particle accelerator emissions. Neutrons that have been slowed through a neutron moderator (thermal neutrons) are more likely to be captured by nuclei than fast neutrons. A less common form of induced radioactivity results from removing a neutron by photodisintegration.
The sparseness of interstellar and interplanetary space results in some unusual chemistry, since symmetry-forbidden reactions cannot occur except on the longest of timescales. For this reason, molecules and molecular ions which are unstable on Earth can be highly abundant in space, for example the H3+ ion. Astrochemistry overlaps with astrophysics and nuclear physics in characterizing the nuclear reactions which occur in stars, the consequences for stellar evolution, as well as stellar 'generations'. Indeed, the nuclear reactions in stars produce every naturally occurring chemical element.
Bowen was able to calculate the forbidden transitions of doubly ionized oxygen to be exactly where the lines had been found. The low probability for collisions in the nebula made it impossible for the oxygen to get from the excited stated to the ground state and so the forbidden transitions were the main path for the relaxation. Bowen published his findings in 1927 and concluded that nebulium was not really a chemical element. Bowen was the first director of the Palomar Observatory, serving from 1948 to 1964.
Neutron matter is equivalent to a chemical element with atomic number 0, which is to say that it is equivalent to a species of atoms having no protons in their atomic nuclei. It is extremely radioactive; its only legitimate equivalent isotope, the free neutron, has a half-life of only 10 minutes, which is comparable to half that of the most stable known isotope of francium. Neutron matter decays quickly into hydrogen. Neutron matter has no electronic structure on account of its total lack of electrons.
Austrium is the name of a new chemical element proposed by Eduard Linnemann in 1886. As a chemist at the German University in Prague he experimented with the mineral orthite (from Arendal in Norway). In the course of his works over several years he detected spectral lines at 4165 and 4030 Angstrom, respectively, which he was not able to ascribe to any then known element. These findings were published only after his death after due consideration on May 6, 1886 by the Academy of Sciences of Prague.
A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with either one or two neutrons, depending on the isotope, held together by the strong force. Unlike for hydrogen, a closed-form solution to the Schrödinger equation for the helium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and wavefunction of the atom.
All isotopes of a chemical element contain the same number of protons with varying numbers of neutrons. The element hydrogen has three naturally occurring isotopes, H, H and H, which are sometimes referred to as protium (H), deuterium (D) and tritium (T), respectively. Both H and H are stable indefinitely, while H is unstable and undergoes beta decay to form He. While there are some important applications of H in geochemistry (such as its use as an ocean circulation tracer) these will not be discussed further here.
Thulium is a chemical element with the symbol Tm and atomic number 69. It is the thirteenth and third-last element in the lanthanide series. Like the other lanthanides, the most common oxidation state is +3, seen in its oxide, halides and other compounds; because it occurs so late in the series, however, the +2 oxidation state is also stabilized by the nearly full 4f shell that results. In aqueous solution, like compounds of other late lanthanides, soluble thulium compounds form coordination complexes with nine water molecules.
OA was first used after World War II by the US railroad industry to monitor the health of locomotives. In 1946 the Denver and Rio Grande Railroad's research laboratory successfully detected diesel engine problems through wear metal analysis of used oils. A key factor in their success was the development of the spectrograph, an instrument which replaced several wet chemical methods for detecting and measuring individual chemical element such as iron or copper. This practice was soon accepted and used extensively throughout the railroad industry.
Victorium, originally named monium, is a mixture of gadolinium and terbium. In 1898, English chemist William Crookes reported his discovery of it in his inaugural address as president of the British Association for the Advancement of Science. He identified the new substance, based on an analysis of the unique phosphorescence and other ultraviolet-visible spectral phenomena, as a new chemical element, although this was later shown to be false. The name monium means "alone", because its spectral lines stood alone at the end of the ultraviolet spectrum.
William Thomson, later to become Lord Kelvin, became concerned with the nature of Dalton's chemical elements, whose atoms appeared in only a few forms but in vast numbers. He was inspired by Helmholz' findings, reasoning that the aether, a substance then hypothesised to pervade all of space, should be capable of supporting such stable vortices. According to Helmholtz’ theorems, these vortices would correspond to different kinds of knot. Thomson suggested that each type of knot might represent an atom of a different chemical element.
Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric.
Magnesium is a chemical element with the symbol Mg and atomic number 12\. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure. Magnesium is the ninth most abundant element in the universe. It is produced in large, aging stars from the sequential addition of three helium nuclei to a carbon nucleus.
In the 1700s and 1800s, scientists Joseph Louis Gay-Lussac and Louis-Jacques Thénard proved sulfur to be a chemical element. Early attempts to separate oxygen from air were hampered by the fact that air was thought of as a single element up to the 17th and 18th centuries. Robert Hooke, Mikhail Lomonosov, Ole Borch, and Pierre Bayden all successfully created oxygen, but did not realize it at the time. Oxygen was discovered by Joseph Priestley in 1774 when he focused sunlight on a sample of mercuric oxide and collected the resulting gas.
Californium is a radioactive chemical element with the symbol Cf and atomic number 98. The element was first synthesized in 1950 at the Lawrence Berkeley National Laboratory (then the University of California Radiation Laboratory), by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second- highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium). The element was named after the university and the state of California.
One hypothesis suggests it is derived from Proto-Indo-European ("lead"; capitalization of the vowel is equivalent to the macron). Another hypothesis suggests it is borrowed from Proto-Celtic ("lead"). This word is related to the Latin , which gave the element its chemical symbol Pb. The word is thought to be the origin of Proto-Germanic (which also means "lead"), from which stemmed the German . The name of the chemical element is not related to the verb of the same spelling, which is derived from Proto-Germanic ("to lead").
The etymology of the name Selenomonas comes from the Ancient Greek noun selênê (σελήνη), meaning the moon, a linking -o- and the noun monas (μόνας) which in microbiology has come to mean bacterium. The name Selenomonas simply refers to the crescent moon-shaped profile of this organism and not in any way to the chemical element selenium. The unique cell morphology of certain large selenomonads (with its in-folding of the cell membrane behind the flagella) would indicate bilateral symmetry along the long axis—an unusual property for prokaryotes.
Around 1993, co-founder Adham told the other executives that he did not like the name "Silicon & Synapse" anymore, as people outside the company were confusing the meaning of silicon the chemical element used in microchips with silicone the materials used in breast implants. By the end of 1993, Adham changed the name to "Chaos Studios", reflecting on the haphazardness of their development processes. In early 1994, they were acquired by distributor Davidson & Associates for $6.75 million ($ million today).Dean Takahashi: game-development Co-Founder Looks at Chaos in Early Stages and Future Challenges.
Graphite ore, shown with a penny for scale Raw diamond crystal dissolved inorganic carbon concentration (from the GLODAP climatology) Carbon is the fourth most abundant chemical element in the observable universe by mass after hydrogen, helium, and oxygen. In July 2020, astronomers reported evidence that carbon was formed mainly in white dwarf stars, particularly those bigger than two solar masses. Carbon is abundant in the Sun, stars, comets, and in the atmospheres of most planets. Some meteorites contain microscopic diamonds that were formed when the solar system was still a protoplanetary disk.
The electrons are placed into atomic orbitals that determine the atom's various chemical properties. The number of neutrons in a nucleus usually has very little effect on an element's chemical properties (except in the case of hydrogen and deuterium). Thus, all carbon isotopes have nearly identical chemical properties because they all have six protons and six electrons, even though carbon atoms may, for example, have 6 or 8 neutrons. That is why the atomic number, rather than mass number or atomic weight, is considered the identifying characteristic of a chemical element.
Waterman joined the University of Vermont's (UVM) College of Arts and Sciences as an assistant professor of chemistry in 2006. His research at UVM focuses on finding new ways to build chemical bonds, specifically in the chemical element Phosphorus. As a result of his research, he received the 2009 Alfred P. Sloan Award for outstanding early career scientists. Beyond this, Waterman also established research opportunities for Vermont high school and University of Vermont undergraduate students which resulted in him winning the 2009 Cottrell Scholar from the Research Corporation for Science Advancement.
The lab was the co-discoverer of new superheavy elements 113, 114, 115, 116, 117, and 118. The chemical element with atomic number 116 was given the name livermorium, after the laboratory, in 2012. LLNL is the location of the world's highest-energy laser, the National Ignition Facility (NIF), a project designed to create the first sustained, controlled nuclear fusion reaction, which would generate fusion power, a potential energy source. Livermore is also the California site of Sandia National Laboratories, which is managed and operated by a subsidiary of Honeywell International.
Karl Ernst Claus (also Karl Klaus or Carl Claus, , 23 January 1796 – 24 March 1864) was a German-Russian chemist and naturalist of Baltic German origin. Claus was a professor at Kazan State University and a member of the Russian Academy of Sciences. He was primarily known as a chemist and discoverer of the chemical element ruthenium, which he named after his homeland of Russia, but also as one of the first scientists who applied quantitative methods in botany.Клаус, Карл Карлович in Волков В.А. et al "Выдающиеся химики мира: Биографический справочник" Moscow, Высш. шк.
Copper is a chemical element with the symbol Cu (from ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.
Colors of a single chemical (Nile red) in different solvents, under visible and UV light, showing how the chemical interacts dynamically with its solvent environment. A chemical substance may well be defined as "any material with a definite chemical composition" in an introductory general chemistry textbook.Hill, J. W.; Petrucci, R. H.; McCreary, T. W.; Perry, S. S. General Chemistry, 4th ed., p5, Pearson Prentice Hall, Upper Saddle River, New Jersey, 2005 According to this definition a chemical substance can either be a pure chemical element or a pure chemical compound.
Protactinium (formerly protoactinium) is a chemical element with the symbol Pa and atomic number 91. It is a dense, silvery-gray actinide metal which readily reacts with oxygen, water vapor and inorganic acids. It forms various chemical compounds in which protactinium is usually present in the oxidation state +5, but it can also assume +4 and even +3 or +2 states. Concentrations of protactinium in the Earth's crust are typically a few parts per trillion, but may reach up to a few parts per million in some uraninite ore deposits.
A technology-critical element (TCE) is a chemical element that is important to emerging technologies, in much higher demand than in the past, and in scarce supply relative to demand. Many advanced engineering applications, like clean- energy production, communications or computing, use emergent technologies that utilize numerous chemical elements. As a result, a much greater proportion of metals in the periodic table are economically significant than in past centuries. Technology-critical elements are those elements for which a striking acceleration in usage has emerged, relative to past consumption.
One of the earliest steps towards atomic physics was the recognition that matter was composed of atoms. It forms a part of the texts written in 6th century BC to 2nd century BC such as those of Democritus or Vaisheshika Sutra written by Kanad. This theory was later developed in the modern sense of the basic unit of a chemical element by the British chemist and physicist John Dalton in the 18th century. At this stage, it wasn't clear what atoms were although they could be described and classified by their properties (in bulk).
Once excited, atoms will lose their energy fairly quickly. Of the various ways that this energy can be lost, the most important is radiatively, meaning that a photon is released to carry the energy away. In optical atomic spectroscopy, the wavelength of this photon can be used to determine the identity of the atom (that is, which chemical element it is) and the number of photons is directly proportional to the concentration of that element in the sample. Some collisions (those of high enough energy) will cause ionization.
Cobalt is a chemical element with the symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought to be due to the known metal bismuth.
Lithium atom A lithium atom is an atom of the chemical element lithium. Lithium is composed of three electrons bound by the electromagnetic force to a nucleus containing three protons along with either three or four neutrons, depending on the isotope, held together by the strong force. Similarly to the case of the helium atom, a closed-form solution to the Schrödinger equation for the lithium atom has not been found. However, various approximations, such as the Hartree–Fock method, can be used to estimate the ground state energy and wavefunction of the atom.
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish- white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it prefers oxidation state +2 in most of its compounds and like mercury it shows a low melting point compared to transition metals. Cadmium and its congeners are not always considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states.
Boron chunks Boron (B) is the chemical element with atomic number 5, occurring as 10B and 11B. At standard temperature and pressure, boron is a trivalent metalloid that has several different allotropes. Amorphous boron is a brown powder formed as a product of many chemical reactions. Crystalline boron is a very hard, black material with a high melting point and exists in many polymorphs: Two rhombohedral forms, α-boron and β-boron containing 12 and 106.7 atoms in the rhombohedral unit cell respectively, and 50-atom tetragonal boron are the most common.
Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226, which has a half-life of 1601 years and decays into radon gas. Because of such instability, radium is luminescent, glowing a faint blue. Radium, in the form of radium chloride, was discovered by Marie Skłodowska-Curie and Pierre Curie in 1898.
Plutonium is a transuranic radioactive chemical element, an actinide metal Actinide chemistry (or actinoid chemistry) is one of the main branches of nuclear chemistry that investigates the processes and molecular systems of the actinides. The actinides derive their name from the group 3 element actinium. The informal chemical symbol An is used in general discussions of actinide chemistry to refer to any actinide. All but one of the actinides are f-block elements, corresponding to the filling of the 5f electron shell; lawrencium, a d-block element, is also generally considered an actinide.
Osmium (from Greek ὀσμή osme, "smell") is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with an experimentally measured (using x-ray crystallography) density of . Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen nib tipping, electrical contacts, and in other applications that require extreme durability and hardness.
Bengt Edlén was born on 2 November 1906 in Gusum, Sweden. He graduated from high school in Norrköping in 1926 and entered the University of Uppsala the same year. He was awarded his bachelor's degree after three semester and graduated with a PhD in 1934 with his thesis about the spectra and energy of the elements in the beginning of the periodic system. He received international fame after finding unidentified spectral lines in the Sun's spectrum which were speculatively believed to originate from a hitherto unidentified chemical element termed coronium.
US Air Force Douglas A-1E Skyraider dropping a 100-pound M47 white phosphorus bomb on a Viet Cong position in South Vietnam in 1966. White phosphorus munitions are weapons which use one of the common allotropes of the chemical element phosphorus. White phosphorus is used in smoke, illumination and incendiary munitions, and is commonly the burning element of tracer ammunition. Other common names include WP and the slang term "Willie Pete" or "Willie Peter" derived from William Peter, the World War II phonetic alphabet for "WP", which is still sometimes used in military jargon.
Radium is a chemical element with the symbol Ra and atomic number 88\. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, but it readily reacts with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra3N2). All isotopes of radium are highly radioactive, with the most stable isotope being radium-226, which has a half- life of 1600 years and decays into radon gas (specifically the isotope radon-222).
Chemical potential was first described by the American engineer, chemist and mathematical physicist Josiah Willard Gibbs. He defined it as follows: Gibbs later noted also that for the purposes of this definition, any chemical element or combination of elements in given proportions may be considered a substance, whether capable or not of existing by itself as a homogeneous body. This freedom to choose the boundary of the system allows the chemical potential to be applied to a huge range of systems. The term can be used in thermodynamics and physics for any system undergoing change.
The enthalpy of atomization (also atomisation in British English) is the enthalpy change that accompanies the total separation of all atoms in a chemical substance (either a chemical element or a chemical compound). This is often represented by the symbol ΔatH or ΔHat. All bonds in the compound are broken in atomization and none are formed, so enthalpies of atomization are always positive. The associated standard enthalpy is known as the Standard enthalpy of atomization, ΔatH ~~o~~ /(kJ mol−1), at 298.15 K (or 25 degrees Celsius) and 100 kPa.
In 1844 Klaus discovered and studied chemical element ruthenium – the single element that was discovered in Russia. Markovnikov has discovered the rule of regioselective addition of acid and water to multiple bonds, on the contrary – Zaitsev – the cleavage of the molecules of acids and water with the formation of unsaturated compounds. Arbuzov, Arbuzov, Pudovik, and Abramov are also widely known in organic and organoelement chemistry.Kazan University: the chronology of foundation of Kazan Chemistry laboratory and Kazan Chemistry school / composed by professor Alexander B. Zakharov; scientific editor Professor Vladimir I. Galkin.
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name zirconium is taken from the name of the mineral zircon (the word is related to Persian zargun (zircon; zar-gun, "gold-like" or "as gold")), the most important source of zirconium. It is a lustrous, grey-white, strong transition metal that closely resembles hafnium and, to a lesser extent, titanium. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion.
An ounce bar of palladium bullion Palladium price 1911–2011 Palladium price 1977–2012 Palladium as an investment is much like investments in other precious metals. Global palladium sales were 8.84 million ounces in 2017 of which 86% was used in the manufacturing of automotive catalytic converters, followed by industrial, jewelry, and investment usages. Palladium is a chemical element first discovered in 1803, and since the 1980s, its major commercial application has been in the automotive industry. More than 75% of global platinum and 40% of palladium are mined in South Africa.
The chemical formula for a molecule uses one line of chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, and plus (+) and minus (−) signs. These are limited to one typographic line of symbols, which may include subscripts and superscripts. A compound's empirical formula is a very simple type of chemical formula. It is the simplest integer ratio of the chemical elements that constitute it. For example, water is always composed of a 2:1 ratio of hydrogen to oxygen atoms, and ethanol (ethyl alcohol) is always composed of carbon, hydrogen, and oxygen in a 2:6:1 ratio.
It comes from careful or careless deliberations, negotiation, discuss, or in the case of YV; incessant community debates and arguments over its origin, originality and suitability. Yabacon is a portmanteau of ‘Yaba’ the Lagos suburb and ‘Silicon’, a chemical element used to create most semiconductors commercially for electronic computers. Although there are technology companies in this area, there are no companies involved in the making of semiconductors since the cluster is still at its green stage and Nigeria is yet to advance to the technology level of manufacturing electronics. Thus, the name is just a sheer but unconscious imitation of America's Silicon valley.
For example, metaclasses could allow a machine reasoner to infer from a human-friendly ontology how many elements are in the periodic table, or, given that number of protons is a property of chemical element and isotopes are a subclass of elements, how many protons exist in the isotope hydrogen-2. Metaclasses are sometime organized by levels, in a similar way to the simple Theory of types where classes that are not metaclasses are assigned the first level, classes of classes in the first level are in the second level, classes of classes in the second level on the next and so on.
Livermorium is a synthetic chemical element with the symbol Lv and has an atomic number of 116. It is an extremely radioactive element that has only been created in the laboratory and has not been observed in nature. The element is named after the Lawrence Livermore National Laboratory in the United States, which collaborated with the Joint Institute for Nuclear Research (JINR) in Dubna, Russia to discover livermorium during experiments made between 2000 and 2006. The name of the laboratory refers to the city of Livermore, California where it is located, which in turn was named after the rancher and landowner Robert Livermore.
Other things associated with fire and yellow bile in ancient and medieval medicine included the season of summer, since it increased the qualities of heat and aridity; the choleric temperament (of a person dominated by the yellow bile humour); the masculine; and the eastern point of the compass. Alchemical symbol for fire In alchemy the chemical element of sulfur was often associated with fire and its alchemical symbol and its symbol was an upward-pointing triangle. In alchemic tradition, metals are incubated by fire in the womb of the Earth and alchemists only accelerate their development.
The ancient Romans instead used lime mortars made by heating limestone (CaCO3); the name "calcium" itself derives from the Latin word calx "lime". Vitruvius noted that the lime that resulted was lighter than the original limestone, attributing this to the boiling of the water; in 1755, Joseph Black proved that this was due to the loss of carbon dioxide, which as a gas had not been recognised by the ancient Romans. In 1787, Antoine Lavoisier suspected that lime might be an oxide of a fundamental chemical element. In his table of the elements, Lavoisier listed five "salifiable earths" (i.e.
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states.
The properties of pure uranium-235 were relatively unknown; even more so those of plutonium, a chemical element that had only recently been discovered by Glenn Seaborg and his team in February 1941, but which was theoretically fissile. The scientists at the Berkeley conference envisioned breeding plutonium in nuclear reactors from uranium-238 atoms that absorbed neutrons from fissioning uranium-235 atoms. At this point no reactor had been built, and only microscopic quantities of plutonium were available that had been produced by cyclotrons. There were many ways of arranging the fissile material into a critical mass.
Unbiquadium, also known as element 124 or eka-uranium, is the hypothetical chemical element with atomic number 124 and placeholder symbol Ubq. Unbiquadium and Ubq are the temporary IUPAC name and symbol, respectively, until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table, unbiquadium is expected to be a g-block superactinide and the sixth element in the 8th period. Unbiquadium has attracted attention, as it may lie within the island of stability, leading to longer half-lives, especially for 308Ubq which is predicted to have a magic number of neutrons (184).
Samarskite specimen, broken to show fresh surface Samarium, element 62 Samarsky-Bykhovets himself was not involved in the studies of samarskite and samarium. As a mining official, he merely granted access to mineral samples from the Urals to the German mineralogist Gustav Rose and his brother Heinrich Rose. Gustav Rose in 1839 described a new mineral in those samples and named it uranotantalum believing that its composition is dominated by the chemical element tantalum. In 1846–47, his brother and colleague-mineralogist Heinrich Rose found that the major component of the mineral is niobium and suggested altering the name to avoid confusion.
The atomic radius of a chemical element is the distance from the centre of the nucleus to the outermost shell of an electron. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently bound in molecules, or in ionized and excited states; and its value may be obtained through experimental measurements, or computed from theoretical models. Under some definitions, the value of the radius may depend on the atom's state and context.
Clarice Evone Phelps () is an American nuclear chemist researching the processing of radioactive transuranic elements at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL). She was part of ORNL's team that collaborated with the Joint Institute for Nuclear Research to discover tennessine (element 117). The International Union of Pure and Applied Chemistry (IUPAC; which, among other responsibilities, coordinates with laboratories and the public for the naming of new chemical elements), recognizes her as the first African-American woman to be involved with the discovery of a chemical element. Phelps was formerly in the US Navy Nuclear Power Program.
In IUPAC's crediting Oak Ridge laboratory collectively as principal co-discoverer of tennessine, it acknowledged 61 individuals at ORNL who had contributed to the project including members of operations staff, support personnel, and researchers such as Phelps. It recognized Phelps as the first African-American woman involved with the discovery of a chemical element. Phelps has contributed to additional research efforts, including those of spectroscopic analysis and spectrophotometric valence state studies of plutonium-238 and neptunium-237 and 238 for the National Aeronautic and Space Administration (NASA). Phelps has also studied electrodeposition with californium-252 for the Californium Rare Isotope Breeder Upgrade project.
By the early 20th century, scientists had developed fairly detailed and precise models for the structure of matter, which led to more rigorously-defined classifications for the tiny invisible particles that make up ordinary matter. An atom is now defined as the basic particle that composes a chemical element. Around the turn of the 20th century, physicists discovered that the particles that chemists called "atoms" are in fact agglomerations of even smaller particles (subatomic particles), but scientists kept the name out of convention. The term elementary particle is now used to refer to particles that are actually indivisible.
Nickel was first isolated and classified as a chemical element in 1751 by Axel Fredrik Cronstedt, who initially mistook the ore for a copper mineral, in the cobalt mines of Los, Hälsingland, Sweden. The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick), who personified the fact that copper-nickel ores resisted refinement into copper. An economically important source of nickel is the iron ore limonite, which often contains 1–2% nickel. Nickel's other important ore minerals include pentlandite and a mixture of Ni-rich natural silicates known as garnierite.
Relative atomic mass is determined by the average atomic mass, or the weighted mean of the atomic masses of all the atoms of a particular chemical element found in a particular sample, which is then compared to the atomic mass of carbon-12. This comparison is the quotient of the two weights, which makes the value dimensionless (no unit appended). This quotient also explains the word relative: the sample mass value is considered relative to that of carbon-12. It is a synonym for atomic weight, though it is not to be confused with relative isotopic mass.
The nuclear strong force has a very short range, and essentially drops to zero just beyond the edge of the nucleus. The collective action of the positively charged nucleus is to hold the electrically negative charged electrons in their orbits about the nucleus. The collection of negatively charged electrons orbiting the nucleus display an affinity for certain configurations and numbers of electrons that make their orbits stable. Which chemical element an atom represents is determined by the number of protons in the nucleus; the neutral atom will have an equal number of electrons orbiting that nucleus.
The nature of the processes in the system determine which balances apply. For a process 'oil refinery', for example, one can establish a mass balance for each chemical element, while this is not possible for a nuclear power station. A car manufacturing plant respects the balance for steel, but a steel mill does not. When quantifying MFA systems either by measurements or from statistical data, mass and other process balances have to be checked to ensure the correctness of the quantification and to reveal possible data inconsistencies or even misconceptions in the system such as the omission of a flow or a process.
In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life. However, the four major structural elements in the human body by weight (oxygen, hydrogen, carbon, and nitrogen), are usually not included in lists of major nutrient minerals (nitrogen is considered a "mineral" for plants, as it often is included in fertilizers). These four elements compose about 96% of the weight of the human body, and major minerals (macrominerals) and minor minerals (also called trace elements) compose the remainder. Nutrient minerals, being elements, cannot be synthesized biochemically by living organisms.
Ytterbium is a soft, malleable and ductile chemical element that displays a bright silvery luster when pure. It is a rare earth element, and it is readily dissolved by the strong mineral acids. It reacts slowly with cold water and it oxidizes slowly in air. Ytterbium has three allotropes labeled by the Greek letters alpha, beta and gamma; their transformation temperatures are −13 °C and 795 °C, although the exact transformation temperature depends on the pressure and stress. The beta allotrope (6.966 g/cm3) exists at room temperature, and it has a face-centered cubic crystal structure.
Zero has been proposed as the atomic number of the theoretical element tetraneutron. It has been shown that a cluster of four neutrons may be stable enough to be considered an atom in its own right. This would create an element with no protons and no charge on its nucleus. As early as 1926, Andreas von Antropoff coined the term neutronium for a conjectured form of matter made up of neutrons with no protons, which he placed as the chemical element of atomic number zero at the head of his new version of the periodic table.
Knots can be tied in the core of such a vortex, leading to the hypothesis that each chemical element corresponds to a different kind of knot. The simple toroidal vortex, represented by the circular "unknot" 01, was thought to represent hydrogen. Many elements had yet to be discovered, so the next knot, the trefoil knot 31, was thought to represent carbon. However, as more elements were discovered and the periodicity of their characteristics established in the periodic table of the elements, it became clear that this could not be explained by any rational classification of knots.
The number of moles of a substance in a sample is obtained by dividing the mass of the sample by the molar mass of the compound. For example, 100 g of water is about 5.551 mol of water. The molar mass of a substance depends not only on its molecular formula, but also on the distribution of isotopes of each chemical element present in it. For example, the mass of one mole of calcium-40 is , whereas the mass of one mole of calcium-42 is , and of one mole of calcium with the normal isotopic mix is .
The main indicator system used to measure China's circular economy is an altered version of the European Union's (EU) material flow analysis (MFA). MFA is a quantitative method of measuring the flow of natural resources and material through various scales of economy, which can range from whole cities to single rivers. It consists of methodically organized indices, where it then uses mass balancing to analyze the relationships between human activities, material flows and environmental degradation. The MFA can be altered to examine anything from all the energy flowing through an economy to single chemical element, such as carbon.
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is considered to be the second-densest metal (after osmium) with a density of as defined by experimental X-ray crystallography. However, at room temperature and standard atmospheric pressure, iridium has been calculated to have a density of , higher than osmium measured the same way. Still, the experimental X-ray crystallography value is considered to be the most accurate, as such iridium is considered to be the second densest element.
Like other Norse goddesses, her name was applied widely in Scandinavia to, for example, "sweetmeats or to stout carthorses". Vanadís, one of Freyja's names, is the source of the name of the chemical element vanadium, so named because of its many colored compounds.. A suburb of Minneapolis, MN, an area settled heavily by Scandinavians, is called "Vanadis Heights". Starting in the early 1990s, derivatives of Freyja began to appear as a given name for girls. According to the Norwegian name database from the Central Statistics Bureau, around 500 women are listed with the first name Frøya (the modern Norwegian spelling of the goddess's name) in the country.
In chemistry, Abegg’s rule states that the difference between the maximum positive and negative valence of an element is frequently eight. The rule used a historic meaning of valence which resembles the modern concept of oxidation state in which an atom is an electron donor or receiver. Abegg’s rule is sometimes referred to as "Abegg’s law of valence and countervalence". In general, for a given chemical element (as sulfur) Abegg’s rule states that the sum of the absolute value of its negative valence (such as −2 for sulfur in H2S and its positive valence of maximum value (as +6 for sulfur in H2SO4) is often equal to 8.
The are Sailor Galaxia's main reapers of starseeds. They bear names prefixed by the title "Sailor" followed by the name of a chemical element (usually a metal or an alloy) and the name of an animal. They are led by Sailor Chi and Sailor Phi in the manga, by Sailor Lead Crow in the anime, and by Sailor Pewter Fox in many of the musicals. Despite the titles, none of them is a true Sailor Guardian but merely normal living-beings who gave up their own star-seeds to Galaxia to become one -- each of them murdered the Guardian of their home planet in order to win Galaxia's favor.
Silicon is a chemical element, a hard dark-grey semiconducting metalloid, which in its crystalline form is used to make integrated circuits ("electronic chips") and solar cells. Silicones are compounds that contain silicon, carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have very different physical and chemical properties. Compounds containing silicon–oxygen double bonds, now called silanones, but which could deserve the name "silicone", have long been identified as intermediates in gas-phase processes such as chemical vapor deposition in microelectronics production, and in the formation of ceramics by combustion. However, they have a strong tendency to polymerize into siloxanes.
Austria's iron and steel industry at Graz, and Czechoslovakia's heavy industry near Prague, which included the mighty Skoda munitions works at Pilsen were, though highly developed, as heavily reliant on imports of raw materials as Germany's. The conquest of Poland brought Germany half a million tons of oil per year and more zinc than it would ever need, and Luxembourg, though tiny, brought a well-organized iron and steel industry 1/7th as great as Germany's. Norway provided good stocks of chromium, aluminum, copper, nickel and 1m annual pounds of molybdenum, the chemical element used in the production of high speed steels and as a substitute for tungsten.
To improve the visually observed contrast of the transition in titration, Mustafin proposed the method of inner light filters. This method consists in the introduction of appropriate indifferent dyes into the reaction system, capable of improving the contrast of the color transition of the indicator at the equivalence point and, thus, to increase the sensitivity of titrimetric determinations. Professor Mustafin actively participated in the compilation of the rational assortment of organic reagents and also in publishing numerous monographs of the series «Organicheskie reagenty dlya opredeleniya neorganicheskikh ionov» (Organic Reagents for Determining Inorganic Ions). Each monograph of this series was devoted to the analytical chemistry of one chemical element.
Polonium is a chemical element with the symbol Po and atomic number 84. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 (with a half-life of 138 days) in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce.
The chemical element of each atom is often indicated by the sphere's color. In a ball-and-stick model, the radius of the spheres is usually much smaller than the rod lengths, in order to provide a clearer view of the atoms and bonds throughout the model. As a consequence, the model does not provide a clear insight about the space occupied by the model. In this aspect, ball-and-stick models are distinct from space-filling (calotte) models, where the sphere radii are proportional to the Van der Waals atomic radii in the same scale as the atom distances, and therefore show the occupied space but not the bonds.
Accordingly, ITS-90 uses numerous defined points, all of which are based on various thermodynamic equilibrium states of fourteen pure chemical elements and one compound (water). Most of the defined points are based on a phase transition; specifically the melting/freezing point of a pure chemical element. However, the deepest cryogenic points are based exclusively on the vapor pressure/temperature relationship of helium and its isotopes whereas the remainder of its cold points (those less than room temperature) are based on triple points. Examples of other defining points are the triple point of hydrogen (−259.3467 °C) and the freezing point of aluminium (660.323 °C).
Helium discharge tube Helium (He) is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas series in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions. Helium was discovered in 1868 by French astronomer Pierre Janssen, who first detected the substance as an unknown yellow spectral line signature in light from a solar eclipse. In 1903, large reserves of helium were found in the natural gas fields of the United States, which is by far the largest supplier of the gas.
After a number of collisions (often in the range of 10–20) with nuclei, neutrons arrive at this energy level, provided that they are not absorbed. In many substances, thermal neutron reactions show a much larger effective cross-section than reactions involving faster neutrons, and thermal neutrons can therefore be absorbed more readily (i.e., with higher probability) by any atomic nuclei that they collide with, creating a heavier – and often unstable – isotope of the chemical element as a result. Most fission reactors use a neutron moderator to slow down, or thermalize the neutrons that are emitted by nuclear fission so that they are more easily captured, causing further fission.
ESOC European Space Operations Command in Darmstadt. Darmstadt is home to many research institutions such as the Fraunhofer Society (Fraunhofer IGD, Fraunhofer LBF, Fraunhofer SIT) and the Gesellschaft für Schwerionenforschung (GSI, "Society for heavy ion Research"), which operates a particle accelerator in northern Darmstadt. The GSI, amongst other elements, discovered the chemical element darmstadtium (atomic number: 110), named after the city in 2003. This makes Darmstadt one of only eight settlements with elements named after them (the others being Ytterby in Sweden (four elements); Stockholm in Sweden (holmium); Strontian in Scotland; Copenhagen in Denmark (whose Latin name gives hafnium); Paris (whose Latin name gives lutetium); Berkeley, California; and Dubna in Russia).
The company derives its name from the chemical element iridium which has an atomic number of 77, equalling the initial number of satellites which were planned to be deployed. The founding company went into Chapter 11 bankruptcy nine months later, on August 13, 1999. The handsets could not operate as promoted until the entire constellation of satellites was in place, requiring a massive initial capital cost running into billions of dollars. The cost of service was prohibitive for many users, reception indoors was difficult and the bulkiness and expense of the hand held devices when compared to terrestrial cellular mobile phones discouraged adoption among potential users.
Relative atomic mass (symbol: A) or atomic weight is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass constant. The atomic mass constant (symbol: m) is defined as being of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative. For a single given sample, the relative atomic mass of a given element is the weighted arithmetic mean of the masses of the individual atoms (including their isotopes) that are present in the sample.
A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol N) and the other represents the number of protons (atomic number, symbol Z) in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element. This system of ordering nuclides can offer a greater insight into the characteristics of isotopes than the better- known periodic table, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after the Italian physicist Emilio Segrè.
Chicago: Rand McNally, 2006, 78. The community of Monroe Furnace was founded around the Monroe Furnace, built in 1855.Lesley, J. Peter, The Iron Manufacturer's Guide to the Furnaces, Forges and Rolling Mills of the United States: With Discussions of Iron as a Chemical Element, and American Ore, and a Manufactured Article, in Commerce and in History, J. Wiley, 1859, Pg. 117. The Monroe Station Post Office was established on October 18, 1861, discontinued on March 21, 1864, re-established on September 29, 1868, discontinued again on February 29, 1884, re-established again on November 30, 1888, and ultimately discontinued again on May 3, 1890.
Rhenium is a chemical element with the symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. Rhenium has the third-highest melting point and second-highest boiling point of any stable element at 5903 K. Rhenium resembles manganese and technetium chemically and is mainly obtained as a by-product of the extraction and refinement of molybdenum and copper ores. Rhenium shows in its compounds a wide variety of oxidation states ranging from −1 to +7.
The overlord having his body rebuilt into a cybernetic augment by replacing his damaged humanoid right arm and lower jaw with mechanical parts (off screen). Now going by the name Trap Jaw, the evil warrior would patiently serve for another chance at taking out his hated master. Later, the cartoon demonstrates that the more metal he eats the stronger he becomes, and one episode focuses on a quest to eat the strongest chemical element in Eternia called Eternium (which was forged and guarded by a group of subterranean dwellers called the Kulatuks). He is defeated by getting tricked into eating a special alloy named Deterninum that weakens him.
These particles have lepton number +1, while their antiparticles have lepton number −1. Since a proton or neutron has lepton number zero, β+ decay (a positron, or antielectron) must be accompanied with an electron neutrino, while β− decay (an electron) must be accompanied by an electron antineutrino. An example of electron emission (β− decay) is the decay of carbon-14 into nitrogen-14 with a half-life of about 5,730 years: : → + + In this form of decay, the original element becomes a new chemical element in a process known as nuclear transmutation. This new element has an unchanged mass number , but an atomic number that is increased by one.
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black non- metallic solid at standard conditions that melts to form a deep violet liquid at 114 degrees Celsius, and boils to a violet gas at 184 degrees Celsius. However, it sublimes easily with gentle heat, resulting in a widespread misconception even taught in some science textbooks that it does not melt. The element was discovered by the French chemist Bernard Courtois in 1811, and was named two years later by Joseph Louis Gay-Lussac, after the Greek ἰώδης "violet-coloured".
Most naturally occurring nuclides are stable (about 252; see list at the end of this article), and about 34 more (total of 286) are known to be radioactive with sufficiently long half-lives (also known) to occur primordially. If the half-life of a nuclide is comparable to, or greater than, the Earth's age (4.5 billion years), a significant amount will have survived since the formation of the Solar System, and then is said to be primordial. It will then contribute in that way to the natural isotopic composition of a chemical element. Primordially present radioisotopes are easily detected with half-lives as short as 700 million years (e.g.
Alternatively, the compound nucleus may eject a few neutrons, which would carry away the excitation energy; if the latter is not sufficient for a neutron expulsion, the merger would produce a gamma ray. This happens in approximately 10−16 seconds after the initial nuclear collision and results in creation of a more stable nucleus. The definition by the IUPAC/IUPAP Joint Working Party (JWP) states that a chemical element can only be recognized as discovered if a nucleus of it has not decayed within 10−14 seconds. This value was chosen as an estimate of how long it takes a nucleus to acquire its outer electrons and thus display its chemical properties.
Unbinilium, also known as eka-radium or simply element 120, is the hypothetical chemical element in the periodic table with symbol Ubn and atomic number 120. Unbinilium and Ubn are the temporary systematic IUPAC name and symbol, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be an s-block element, an alkaline earth metal, and the second element in the eighth period. It has attracted attention because of some predictions that it may be in the island of stability, although newer calculations expect the island to actually occur at a slightly lower atomic number, closer to copernicium and flerovium.
The article in Pravda as of 20 March 1943 stated that "Our [Soviet] people have fallen in love with the Ural's old storyteller P. Bazhov".Bazhov 1952 (1), p. 242. The flag of Polevskoy (from left to right): the Venus symbol (♀), which represents the chemical element copper and was the brand of the Polevskoy Copper Smelting Plant, the Mistress of the Copper Mountain depicted as the golden lizard, the symbolic representation of the Stone Flower from the story of the same name, and the eight-pointed star, the brand of the Seversky Pipe Plant. Selected stories have been a part of school core curriculum since the Soviet Union, and are still used for education purposes nowadays.
Nitrogen-14 is one of two stable (non-radioactive) isotopes of the chemical element nitrogen, which makes about 99.636% of natural nitrogen. Nitrogen-14 is one of the very few stable nuclides with both an odd number of protons and of neutrons (seven each) and is the only one to make up a majority of its element. Each of proton or neutron contributes a nuclear spin of plus or minus spin 1/2, giving the nucleus a total magnetic spin of one. Like all elements heavier than lithium, the original source of nitrogen-14 and nitrogen-15 in the Universe is believed to be stellar nucleosynthesis, where they are produced as part of the carbon- nitrogen-oxygen cycle.
Autotrophs produce usable energy (in the form of organic compounds) using light from the sun or inorganic compounds while heterotrophs take in organic compounds from the environment. The primary chemical element in these compounds is carbon. The chemical properties of this element such as its great affinity for bonding with other small atoms, including other carbon atoms, and its small size making it capable of forming multiple bonds, make it ideal as the basis of organic life. It is able to form small three-atom compounds (such as carbon dioxide), as well as large chains of many thousands of atoms that can store data (nucleic acids), hold cells together, and transmit information (protein).
The history of the discovery and use of the elements began with primitive human societies that discovered native minerals like carbon, sulfur, copper and gold (though the concept of a chemical element was not yet understood). Attempts to classify materials such as these resulted in the concepts of classical elements, alchemy, and various similar theories throughout human history. Much of the modern understanding of elements is attributed to Dmitri Mendeleev, a Russian chemist who published the first recognizable periodic table in 1869. The properties of the chemical elements are summarized in this table, which organizes them by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties.
Unbihexium, also known as element 126 or eka-plutonium, is the hypothetical chemical element with atomic number 126 and placeholder symbol Ubh. Unbihexium and Ubh are the temporary IUPAC name and symbol, respectively, until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table, unbihexium is expected to be a g-block superactinide and the eighth element in the 8th period. Unbihexium has attracted attention among nuclear physicists, especially in early predictions targeting properties of superheavy elements, for 126 may be a magic number of protons near the center of an island of stability, leading to longer half-lives, especially for 310Ubh or 354Ubh which may also have magic numbers of neutrons.
Fluorescent materials are used in applications in which the phosphor is excited continuously: cathode ray tubes (CRT) and plasma video display screens, fluoroscope screens, fluorescent lights, scintillation sensors, and white LEDs, and luminous paints for black light art. Phosphorescent materials are used where a persistent light is needed, such as glow-in-the-dark watch faces and aircraft instruments, and in radar screens to allow the target 'blips' to remain visible as the radar beam rotates. CRT phosphors were standardized beginning around World War II and designated by the letter "P" followed by a number. Phosphorus, the light- emitting chemical element for which phosphors are named, emits light due to chemiluminescence, not phosphorescence.
In chemistry, the number of protons in the nucleus of an atom is known as the atomic number, which determines the chemical element to which the atom belongs. For example, the atomic number of chlorine is 17; this means that each chlorine atom has 17 protons and that all atoms with 17 protons are chlorine atoms. The chemical properties of each atom are determined by the number of (negatively charged) electrons, which for neutral atoms is equal to the number of (positive) protons so that the total charge is zero. For example, a neutral chlorine atom has 17 protons and 17 electrons, whereas a Cl− anion has 17 protons and 18 electrons for a total charge of −1.
The chemical state of a chemical element is due to its electronic, chemical and physical properties as it exists in combination with itself or a group of one or more other elements. A chemical state is often defined as an "oxidation state" when referring to metal cations. When referring to organic materials, a chemical state is usually defined as a chemical group, which is a group of several elements bonded together. Material scientists, solid state physicists, analytical chemists, surface scientists and spectroscopists describe or characterize the chemical, physical and/or electronic nature of the surface or the bulk regions of a material as having or existing as one or more chemical states.
These are the strata that make up the glide plane of the Lower Gros Ventre Slide east of the park. The Phosphoria Formation and its equivalents of Permian age are unlike any other Paleozoic rocks because of their extraordinary content of uncommon elements. The formation consists of sandy dolomite, widespread black phosphate beds and black shale that is unusually rich not only in phosphorus, but also in vanadium, uranium, chromium, zinc, selenium, molybdenum, cobalt, and silver. The formation is mined extensively in nearby parts of Idaho and in Wyoming for phosphatic fertilizer, for the chemical element phosphorus, and for some of the metals that can be derived from the rocks as by-products.
Segrè was appointed assistant professor of physics at the University of Rome in 1932 and worked there until 1936, becoming one of the Via Panisperna boys. From 1936 to 1938 he was director of the Physics Laboratory at the University of Palermo. After a visit to Ernest O. Lawrence's Berkeley Radiation Laboratory, he was sent a molybdenum strip from the laboratory's cyclotron deflector in 1937, which was emitting anomalous forms of radioactivity. After careful chemical and theoretical analysis, Segrè was able to prove that some of the radiation was being produced by a previously unknown element, named technetium, which was the first artificially synthesized chemical element that does not occur in nature.
Among the subjects of special pride are the creation of non-Euclidean geometry by Nikolai Lobachevsky, the discovery of the chemical element Ruthenium by Karl Klauss, the theory of chemical structure of organic compounds by Aleksandr Butlerov, the discovery of electron paramagnetic resonance by Yevgeny Zavoisky and acoustic paramagnetic resonance by Semen Altshuler, the development of organophosphorus chemical compounds by Alexander and Boris Arbuzovs and many others. Since its inception, the university has prepared more than 70 thousand professionals. Among the university students and alumni there are outstanding scholars and famous people such as the founder of the Soviet Union Vladimir Lenin, writers Sergei Aksakov, Leo Tolstoy, Pavel Melnikov-Pechersky, Velimir Khlebnikov, composer Mily Balakirev, and painter Valery Yakobi.
Dietary supplements can be formulated to contain several different chemical elements (as compounds), a combination of vitamins and/or other chemical compounds, or a single element (as a compound or mixture of compounds), such as calcium (calcium carbonate, calcium citrate) or magnesium (magnesium oxide), or iron (ferrous sulfate, iron bis-glycinate). The dietary focus on chemical elements derives from an interest in supporting the biochemical reactions of metabolism with the required elemental components. Appropriate intake levels of certain chemical elements have been demonstrated to be required to maintain optimal health. Diet can meet all the body's chemical element requirements, although supplements can be used when some recommendations are not adequately met by the diet.
Xenoparasitic complex was the term initially devised in the early twentieth century to describe specific type 'tumours' found on various organisms, specific as the infections were caused by multiple subclasses of microsporidia. A paper published in 1922 by Weissenberg came up with the term 'xenon' for the xenoparasitic complexes he observed on sticklebacks caused by Glugea anomala, before eventually changing it to xenoma (xenon was already the name of a newly discovered chemical element). Hypertrophy of cells caused by protists and fungi has been observed since the late nineteenth century. Scientists observed them in several organisms, of which the infection would have varied host cell specificity, ultimately leading to different cellular consequences.
They are part of the class of electrons because they are electrons. In Armstrong's view, nominalisms can also be criticised for producing a blob theory of reality. Objects have structure: they have parts, those parts are made of molecules, which are in turn made up of atoms standing in relation to one another, which are in turn made up of subatomic particles and so on. Blobbiness also threatens Platonic universals: a particular instantiating a universal in a world of Platonic universals becomes a matter of the blob- particular having a relation to a universal elsewhere (in the Platonic heaven, say), rather than having an internal relation in the way that a chemical element does to a constituent atom.
Unbibium, also known as element 122 or eka-thorium, is the hypothetical chemical element in the periodic table with the placeholder symbol of Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides and the fourth element of the 8th period. Similarly to unbiunium, it is expected to fall within the range of the island of stability, potentially conferring additional stability on some isotopes, especially 306Ubb which is expected to have a magic number of neutrons (184).
The Bohr model of the Hydrogen atom One of the earliest steps towards atomic physics was the recognition that matter was composed of atoms, in modern terms the basic unit of a chemical element. This theory was developed by John Dalton in the 18th century. At this stage, it wasn't clear what atoms were - although they could be described and classified by their observable properties in bulk; summarized by the developing periodic table, by John Newlands and Dmitri Mendeleyev around the mid to late 19th century. Later, the connection between atomic physics and optical physics became apparent, by the discovery of spectral lines and attempts to describe the phenomenon - notably by Joseph von Fraunhofer, Fresnel, and others in the 19th century.
Potash is primarily a mixture of potassium salts because plants have little or no sodium content, and the rest of a plant's major mineral content consists of calcium salts of relatively low solubility in water. While potash has been used since ancient times, its composition was not understood. Georg Ernst Stahl obtained experimental evidence that led him to suggest the fundamental difference of sodium and potassium salts in 1702, and Henri Louis Duhamel du Monceau was able to prove this difference in 1736. The exact chemical composition of potassium and sodium compounds, and the status as chemical element of potassium and sodium, was not known then, and thus Antoine Lavoisier did not include the alkali in his list of chemical elements in 1789.
This convention, while less important in a relatively simple formula, means that mathematicians can more quickly manipulate formulas which are larger and more complex. Mathematical formulas are often algebraic, analytical or in closed form. In modern chemistry, a chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using a single line of chemical element symbols, numbers, and sometimes other symbols, such as parentheses, brackets, and plus (+) and minus (−) signs.Atkins, P.W., Overton, T., Rourke, J., Weller, M. and Armstrong, F. Shriver and Atkins inorganic chemistry (4th edition) 2006 (Oxford University Press) For example, H2O is the chemical formula for water, specifying that each molecule consists of two hydrogen (H) atoms and one oxygen (O) atom.
Kappa Pavonis is a W Virginis variable—a subclass of Type II Cepheid. It ranges from magnitude 3.91 to 4.78 over 9 days and is a yellow-white supergiant pulsating between spectral classes F5I-II and G5I-II. NU and V Pavonis are pulsating semiregular variable red giant stars. NU has a spectral type M6III and ranges from magnitude 4.9 to 5.3, while V Pavonis ranges from magnitude 6.3 to 8.2 over two periods of 225.4 and 3735 days concurrently. V is a carbon starC6 is equivalent to a class M2–M3 star, the 4 shows the strength of the Swan bands on a scale of 1 (weak) to 5 (strong), and the Nb indicates bands of the chemical element niobium.
A carbon-13 label was used to determine the mechanism in the 1,2- to 1,3-didehydrobenzene conversion of the phenyl substituted aryne precursor 1 to acenaphthylene. An isotopic tracer, (also "isotopic marker" or "isotopic label"), is used in chemistry and biochemistry to help understand chemical reactions and interactions. In this technique, one or more of the atoms of the molecule of interest is substituted for an atom of the same chemical element, but of a different isotope (like a radioactive isotope used in radioactive tracing). Because the labeled atom has the same number of protons, it will behave in almost exactly the same way as its unlabeled counterpart and, with few exceptions, will not interfere with the reaction under investigation.
Ida Noddack was nominated three times for the Nobel Prize in Chemistry. ;Seaborgium : Carol Alonso was a co-discoverer of Seaborgium, a synthetic chemical element with symbol Sg and atomic number 106.A. Ghiorso, J. M. Nitschke, J. R. Alonso, C. T. Alonso, M. Nurmia, G. T. Seaborg, E. K. Hulet and R. W. Lougheed, Physical Review Letters 33, 1490 (1974) ;Scotchgard :This stain repellent and durable water repellent was co-invented by chemists Patsy Sherman and Samuel Smith while working for 3M. ;Langmuir–Blodgett film :The technique for making Langmuir–Blodgett film, which involves immersing a substrate into a solution to deposit a monolayer of molecules onto a substrate, was co-invented by Katharine Burr Blodgett and Irving Langmuir while working for General Electric.
Life on Earth is based on carbon and water. Carbon provides stable frameworks for complex chemicals and can be easily extracted from the environment, especially from carbon dioxide. There is no other chemical element whose properties are similar enough to carbon's to be called an analogue; silicon, the element directly below carbon on the periodic table, does not form very many complex stable molecules, and because most of its compounds are water-insoluble and because silicon dioxide is a hard and abrasive solid in contrast to carbon dioxide at temperatures associated with living things, it would be more difficult for organisms to extract. The elements boron and phosphorus have more complex chemistries, but suffer from other limitations relative to carbon.
The character 燐 at that time in China could also mean the luminescence of fireflies, triboelectricity, and was not a word that indicated the chemical element "phosphorus". Meanwhile, in Japan, according to the explanation in the "Wakan Sansai Zue", for humans, horses, and cattle die in battle and stain the ground with blood, the onibi are what their spirits turn into after several years and months. One century after the "Wakan Sansai Zue" in the 19th century and afterwards in Japan, as the first to speak of them, they were mentioned in Shūkichi Arai's literary work "Fushigi Benmō", stating, "the corpses of those who are buried have their phosphorus turned into onibi". This interpretation was supported until the 1920s, and dictionaries would state this in the Shōwa period and beyond.
Strong spectral lines in the visible part of the spectrum often have a unique Fraunhofer line designation, such as K for a line at 393.366 nm emerging from singly-ionized Ca+, though some of the Fraunhofer "lines" are blends of multiple lines from several different species. In other cases the lines are designated according to the level of ionization by adding a Roman numeral to the designation of the chemical element, so that Ca+ also has the designation Ca II or CaII. Neutral atoms are denoted with the Roman numeral I, singly ionized atoms with II, and so on, so that, for example, FeIX (IX, Roman nine) represents eight times ionized iron. More detailed designations usually include the line wavelength and may include a multiplet number (for atomic lines) or band designation (for molecular lines).
The oblique form is seen in the Italian and Russian names for the asteroid, Pallade and Паллада Pallada.The one exception internationally to the use of Pallas/Pallad- as the name of the asteroid is Chinese, where it is known as 智神星 Zhìshénxīng, the 'wisdom-god star' (There are several male characters with a similar same name in Greek mythology, Pállas rather than Pallás, but the first asteroids were invariably given female names. Because the oblique stem is different, the male name would have been Pallante in Italian and Паллант Pallant in Russian.) The stony-iron Pallasite meteorites are not Palladian, being named instead after the German naturalist Peter Simon Pallas. The chemical element palladium, on the other hand, was named after the asteroid, which had been discovered just before the element.
This is a list of the 118 chemical elements which have been identified as of 2020. A chemical element, often simply called an element, is a species of atoms which all have the same number of protons in their atomic nuclei (i.e., the same atomic number, or Z). A popular visualization of all 118 elements is the periodic table of the elements, a convenient tabular arrangement of the elements by their chemical properties that uses abbreviated chemical symbols in place of full element names, but the simpler list format presented here may also be useful. Like the periodic table, the list below organizes the elements by the number of protons in their atoms; it can also be organized by other properties, such as atomic weight, density, and electronegativity.
Positron decay results in nuclear transmutation, changing an atom of one chemical element into an atom of an element with an atomic number that is less by one unit. Positron emission occurs only very rarely naturally on earth, when induced by a cosmic ray or from one in a hundred thousand decays of potassium-40, a rare isotope, 0.012% of that element on earth. Positron emission should not be confused with electron emission or beta minus decay (β− decay), which occurs when a neutron turns into a proton and the nucleus emits an electron and an antineutrino. Positron emission is different from proton decay, the hypothetical decay of protons, not necessarily those bound with neutrons, not necessarily through the emission of a positron and not as part of nuclear physics, but rather of particle physics.
Nuclear fission differs importantly from other types of nuclear reactions, in that it can be amplified and sometimes controlled via a nuclear chain reaction (one type of general chain reaction). In such a reaction, free neutrons released by each fission event can trigger yet more events, which in turn release more neutrons and cause more fission. The chemical element isotopes that can sustain a fission chain reaction are called nuclear fuels, and are said to be fissile. The most common nuclear fuels are 235U (the isotope of uranium with mass number 235 and of use in nuclear reactors) and 239Pu (the isotope of plutonium with mass number 239). These fuels break apart into a bimodal range of chemical elements with atomic masses centering near 95 and 135 u (fission products).
Relative isotopic mass (a property of a single atom) is not to be confused with the averaged quantity atomic weight (see above), that is an average of values for many atoms in a given sample of a chemical element. While atomic mass is an absolute mass, relative isotopic mass is a dimensionless number with no units. This loss of units results from the use of a scaling ratio with respect to a carbon-12 standard, and the word "relative" in the term "relative isotopic mass" refers to this scaling relative to carbon-12. The relative isotopic mass, then, is the mass of a given isotope (specifically, any single nuclide), when this value is scaled by the mass of carbon-12, where the latter has to be determined experimentally.
A thermal neutron is a free neutron with a kinetic energy of about 0.025 eV (about 4.0×10−21 J or 2.4 MJ/kg, hence a speed of 2.19 km/s), which is the most probable energy at a temperature of 290 K (17 °C or 62 °F), the mode of the Maxwell–Boltzmann distribution for this temperature. After a number of collisions with nuclei (scattering) in a medium (neutron moderator) at this temperature, those neutrons which are not absorbed reach about this energy level. Thermal neutrons have a different and sometimes much larger effective neutron absorption cross-section for a given nuclide than fast neutrons, and can therefore often be absorbed more easily by an atomic nucleus, creating a heavier, often unstable isotope of the chemical element as a result. This event is called neutron activation.
Heavier metals, such as iron, are partially ionized and have lost most of the external electrons. The ionization state of a chemical element depends strictly on the temperature and is regulated by the Saha equation in the lowest atmosphere, but by collisional equilibrium in the optically-thin corona. Historically, the presence of the spectral lines emitted from highly ionized states of iron allowed determination of the high temperature of the coronal plasma, revealing that the corona is much hotter than the internal layers of the chromosphere. The corona behaves like a gas which is very hot but very light at the same time: the pressure in the corona is usually only 0.1 to 0.6 Pa in active regions, while on the Earth the atmospheric pressure is about 100 kPa, approximately a million times higher than on the solar surface.
In chemistry, a mixed oxide is a somewhat informal name for an oxide that contains cations of more than one chemical element or cations of a single element in several states of oxidation.Advanced Inorganic Chemistry, F. A. Cotton, G. Wilkinson, Interscience, 2d Edition, 1966 The term is usually applied to solid ionic compounds that contain the oxide anion O2− and two or more element cations. Typical examples are ilmenite (FeTiO3), a mixed oxide of iron (Fe2+) and titanium (Ti4+) cations, perovskite and garnet. The cations may be the same element in different ionization states: a notable example is magnetite Fe3O4, which contains the cations Fe2+ ("ferrous" iron) and Fe3+ ("ferric" iron) in 1:2 ratio. Other notable examples include red lead , the ferrites,Alex Goldman (1990), Modern ferrite technology and the yttrium aluminum garnet Y3Al5O12,K.
For example, the light, or electromagnetic radiation emitted or absorbed by an atom has only certain frequencies (or wavelengths), as can be seen from the line spectrum associated with the chemical element represented by that atom. The quantum theory shows that those frequencies correspond to definite energies of the light quanta, or photons, and result from the fact that the electrons of the atom can have only certain allowed energy values, or levels; when an electron changes from one allowed level to another, a quantum of energy is emitted or absorbed whose frequency is directly proportional to the energy difference between the two levels. The photoelectric effect further confirmed the quantization of light. In 1924, Louis de Broglie proposed that not only do light waves sometimes exhibit particle-like properties, but particles may also exhibit wave-like properties.
Unbiunium, also known as eka-actinium or simply element 121, is the hypothetical chemical element with symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to be the first of the superactinides, and the third element in the eighth period: analogously to lanthanum and actinium, it could be considered the fifth member of group 3 and the first member of the fifth-row transition metals, although element 157 may instead take that position. It has attracted attention because of some predictions that it may be in the island of stability, although newer calculations expect the island to occur at a slightly lower atomic number, closer to copernicium and flerovium.
The discrete part of the emission spectrum of hydrogen Spectrum of sunlight above the atmosphere (yellow) and at sea level (red), revealing an absorption spectrum with a discrete part (such as the line due to ) and a continuous part (such as the bands labeled ) A physical quantity is said to have a discrete spectrum if it takes only distinct values, with gaps between one value and the next. The classical example of discrete spectrum (for which the term was first used) is the characteristic set of discrete spectral lines seen in the emission spectrum and absorption spectrum of isolated atoms of a chemical element, which only absorb and emit light at particular wavelengths. The technique of spectroscopy is based on this phenomenon. Discrete spectra are contrasted with the continuous spectra also seen in such experiments, for example in thermal emission, in synchrotron radiation, and many other light- producing phenomena.
The nucleus can also be modified through bombardment by high energy subatomic particles or photons. If this modifies the number of protons in a nucleus, the atom changes to a different chemical element. If the mass of the nucleus following a fusion reaction is less than the sum of the masses of the separate particles, then the difference between these two values can be emitted as a type of usable energy (such as a gamma ray, or the kinetic energy of a beta particle), as described by Albert Einstein's mass-energy equivalence formula, E=mc^2, where m is the mass loss and c is the speed of light. This deficit is part of the binding energy of the new nucleus, and it is the non-recoverable loss of the energy that causes the fused particles to remain together in a state that requires this energy to separate.
In the early 1800s, the scientist John Dalton noticed that chemical substances seemed to combine and break down into other substances by weight in proportions that suggested that each chemical element is ultimately made up of tiny indivisible particles of consistent weight. Shortly after 1850, certain physicists developed the kinetic theory of gases and of heat, which mathematically modelled the behavior of gases by assuming that they were made of particles. In the early 20th century, Albert Einstein and Jean Perrin proved that Brownian motion (the erratic motion of pollen grains in water) is caused by the action of water molecules; this third line of evidence silenced remaining doubts among scientists as to whether atoms and molecules were real. Throughout the nineteenth century, some scientists had cautioned that the evidence for atoms was indirect, and therefore atoms might not actually be real, but only seem to be real.
Work with the chemical element xenon gave important confirmation of Paul Dirac's quantum field theory. In 1937 he became an Associate Professor in Natural Philosophy, and second-in-charge of the Natural Philosophy Department. With the outbreak of the Second World War in September 1939, Martin commenced projects at the request of the Australian Defence Forces, investigating a proximity fuse for the Australian Army and an acoustic communications system for the Royal Australian Air Force (RAAF) that would allow an instructor and trainee pilot to converse with each other. He led a team that built a prototype Height and Range Finder No. 3, Mark IV, for the Army, but the Army cancelled the order in August 1941 when the prototype was nearly complete. In January 1942, he was seconded to the Council for Scientific and Industrial Research's Radiophysics Laboratory in Sydney to develop secret valves for a Radio Direction Finder.
In the 1860s, Stanislao Cannizzaro refined relative atomic masses by applying Avogadro's law (notably at the Karlsruhe Congress of 1860). He formulated a law to determine relative atomic masses of elements: the different quantities of the same element contained in different molecules are all whole multiples of the atomic weight and determined relative atomic masses and molecular masses by comparing the vapor density of a collection of gases with molecules containing one or more of the chemical element in question. In the 20th century, until the 1960s, chemists and physicists used two different atomic- mass scales. The chemists used a "atomic mass unit" (amu) scale such that the natural mixture of oxygen isotopes had an atomic mass 16, while the physicists assigned the same number 16 to only the atomic mass of the most common oxygen isotope (16O, containing eight protons and eight neutrons).
Isadore Perlman (April 12, 1915 – August 3, 1991) was an American nuclear chemist noted for his research of Alpha particle decay. Isadore Perlman; Nuclear Chemist, Expert on Alpha Particle Decay;August 09, 1991 Isadore Perlman; by Glenn T. Seaborg and Frank Asaro University of California:In Memoriam The National Academy of Sciences called Perlman "a world leader on the systematics of alpha decay". He was also recognized for his research of nuclear structure of the heavy elements. He was also noted for his isolation of Curium, New York Times: Outstanding Events of 1947, Isadore Perlman in isolating curium, the heaviest known chemical element and the most violently radioactive;By WALDEMAR KAEMPFFERT;December 28, 1947, New York Times:Curium, Man-Made Element 96, Is Isolated in Visible Quantity; Chemists at City Session Hear of the Violently Radioactive Solid -- Photo of Glowing Salt Solution Is Displayed ELEMENT CURIUM VISIBLY ISOLATED;By WILLIAM L. LAURENCE;September 17, 1947, as well as for fission of tantalum, bismuth, lead, thallium and platinum.
Boyle first argued that fire is not a universal and sufficient analyzer of dividing all bodies into their elements, contrary to Jean Beguin and Joseph Duchesne. To prove this he turned for support to Jan Baptist van Helmont whose Alkahest was reputed to be a universal analyzer. Boyle rejected the Aristotelian theory of the four elements (earth, air, fire, and water) and also the three principles (salt, sulfur, and mercury) proposed by Paracelsus. After discussing the classical elements and chemical principles in the first five parts of the book, in the sixth part Boyle defines chemical element in a manner that approaches more closely to the modern concept: :I now mean by Elements, as those Chymists that speak plainest do by their Principles, certain Primitive and Simple, or perfectly unmingled bodies; which not being made of any other bodies, or of one another, are the Ingredients of all those call'd perfectly mixt Bodies are immediately compounded, and into which they are ultimately resolved.
The Mistress of the Copper Mountain and Tanyushka The coat of arms of Polevskoy (from left to right): the Venus symbol (♀), which represents the chemical element copper and was the brand of the Polevskoy Copper Smelting Plant, the Mistress of the Copper Mountain depicted as the golden lizard, and the eight-pointed star, the brand of the Seversky Pipe Plant. The Mistress of the Copper Mountain (), also known as The Malachite Maid, is a legendary creature from Slavic mythology and a Russian fairy tale character, the mountain spirit from the legends of the Ural miners and the Mistress of the Ural Mountains of Russia. In the national folktales and legends, she is depicted as an extremely beautiful green-eyed young woman in a malachite gown or as a lizard with a crown. She has been viewed as the patroness of miners, the protector and owner of hidden underground riches, the one who can either permit or prevent the mining of stones and metals in certain places.
The idea that all matter is fundamentally composed of elementary particles dates from at least the 6th century BC. In the 19th century, John Dalton, through his work on stoichiometry, concluded that each element of nature was composed of a single, unique type of particle. The word atom, after the Greek word atomos meaning "indivisible", has since then denoted the smallest particle of a chemical element, but physicists soon discovered that atoms are not, in fact, the fundamental particles of nature, but are conglomerates of even smaller particles, such as the electron. The early 20th century explorations of nuclear physics and quantum physics led to proofs of nuclear fission in 1939 by Lise Meitner (based on experiments by Otto Hahn), and nuclear fusion by Hans Bethe in that same year; both discoveries also led to the development of nuclear weapons. Throughout the 1950s and 1960s, a bewildering variety of particles were found in collisions of particles from beams of increasingly high energy.
Since the onset of concerns regarding diamond origins, research has been conducted to determine if the mining location could be determined for an emerald already in circulation. Traditional research used qualitative guidelines such as an emerald's color, style and quality of cutting, type of fracture filling, and the anthropological origins of the artifacts bearing the mineral to determine the emerald's mine location. More recent studies using energy dispersive X-ray spectroscopy methods have uncovered trace chemical element differences between emeralds, including ones mined in close proximity to one another. American gemologist David Cronin and his colleagues have extensively examined the chemical signatures of emeralds resulting from fluid dynamics and subtle precipitation mechanisms, and their research demonstrated the chemical homogeneity of emeralds from the same mining location and the statistical differences that exist between emeralds from different mining locations, including those between the three locations: Muzo, Coscuez, and Chivor, in Colombia, South America.
A gifted botanist blessed also with a gardener's eye for beauty, George Don was enthusiastic in his praise for the two plant species for which he created the new genus Physochlaina, noting in his ' A General History... ' of 1838 : > 'The species of Physochlaina are extremely desirable plants; being early > flowerers, and elegant when in blossom. They will grow in any soil, and are > readily propagated by divisions of the root, or by seed. They are well > adapted for decorating borders in early spring'. In regard to the soil type favoured by wild populations, volume 22 of Linnaea (in surprisingly geological vein) provides the observation that Physochlaina orientalis is to be found growing on soils underlain by trachytes (volcanic rocks of a type notably rich in the chemical element potassium, a plant macronutrient essential for the production of flowers and fruit and, in a specifically Solanaceous context, the main ingredient of liquid feed for tomato plants).
300pxIn physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an isotope varies from planet to planet, and even from place to place on the Earth, but remains relatively constant in time (on a short- term scale). As an example, uranium has three naturally occurring isotopes: 238U, 235U and 234U. Their respective natural mole-fraction abundances are 99.2739–99.2752%, 0.7198–0.7202%, and 0.0050–0.0059%. For example, if 100,000 uranium atoms were analyzed, one would expect to find approximately 99,274 238U atoms, approximately 720 235U atoms, and very few (most likely 5 or 6) 234U atoms. This is because 238U is much more stable than 235U or 234U, as the half-life of each isotope reveals: 4.468 × 109 years for 238U compared with 7.038 × 108 years for 235U and 245,500 years for 234U. Exactly because the different uranium isotopes have different half-lives, when the Earth was younger, the isotopic composition of uranium was different.
It is a two-dimensional graphical representation in the Segrè-arrangement with the neutron number N on the abscissa and the proton number Z on the ordinate. Each nuclide is represented at the intersection of its respective neutron and proton number by a small square box with the chemical symbol and the nucleon number A. By columnar subdivision of such a field, in addition to ground states also nuclear isomers can be shown. The coloring of a field (segmented if necessary) shows in addition to the existing text entries the observed types of radioactive decay of the nuclide and a rough classification of their relative shares: stable, nonradioactive nuclides completely black, primordial radionuclides partially black, proton emission orange, alpha decay yellow, beta plus decay/electron capture red, isomeric transition (gamma decay, internal conversion) white, beta minus decay blue, spontaneous fission green, cluster emission violet, neutron emission light blue. For each radionuclide its field includes (if known) information about its half-life and essential energies of the emitted radiation, for stable nuclides and primordial radionuclides there are data on mole fraction abundances in the natural isotope mixture of the corresponding chemical element.
By definition, any two atoms with an identical number of protons in their nuclei belong to the same chemical element. Atoms with equal numbers of protons but a different number of neutrons are different isotopes of the same element. For example, all hydrogen atoms admit exactly one proton, but isotopes exist with no neutrons (hydrogen-1, by far the most common form, also called protium), one neutron (deuterium), two neutrons (tritium) and more than two neutrons. The known elements form a set of atomic numbers, from the single-proton element hydrogen up to the 118-proton element oganesson. All known isotopes of elements with atomic numbers greater than 82 are radioactive, although the radioactivity of element 83 (bismuth) is so slight as to be practically negligible. About 339 nuclides occur naturally on Earth, of which 252 (about 74%) have not been observed to decay, and are referred to as "stable isotopes". Only 90 nuclides are stable theoretically, while another 162 (bringing the total to 252) have not been observed to decay, even though in theory it is energetically possible. These are also formally classified as "stable". An additional 34 radioactive nuclides have half-lives longer than 100 million years, and are long-lived enough to have been present since the birth of the solar system.

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