query: what do helium argon and neon have in common

pos: Noble gas factors, including the following: Noble gas The noble gases (historically also the inert gases; sometimes referred to as aerogens) make up a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). These elements are all nonmetals. Oganesson (Og) is variously predicted to be a noble gas as well or to break the trend due to relativistic effects; its chemistry has not yet been investigated.

pos: Compounds of fluorine gases (helium through argon) do not form stable binary fluorides. Argon forms no binary fluoride, but reacts in extreme conditions with hydrogen fluoride to form argon fluorohydride; it is the only "stable" argon compound. Helium and neon do not form any stable chemical compounds at all. Helium forms helium fluorohydride; it has been shown to be unstable in gas phase, but there are specific conditions for which it may be stable. Neon, the least reactive element, is not now expected to form a stable compound capable of synthesis. Oganesson, the last currently known group 18 element, is predicted to form

pos: Penning mixture mixture used in plasma displays is usually helium or neon with small percentage of xenon, at several hundred torr. Penning mixtures with the formulas of argon-xenon, neon-argon, argon-acetylene, and xenon-TMA are used as filler gases in gaseous ionization detectors. Other kinds of Penning mixture include helium-xenon. Penning mixture A Penning mixture, named after Frans Michel Penning, is a mixture of gases used in electric lighting or displaying fixtures. Although the popular phrase for the most common of these is a neon lamp, it is more efficient to have the glass tube filled not with pure neon, but with a Penning

pos: Neon sign are the most common gases used; krypton, xenon, and helium are used by artists for special purposes but are not used alone in normal signs. A premixed combination of argon and helium is often used in lieu of pure argon when a tube is to be installed in a cold climate, since the helium increases voltage drop (and thus power dissipation), warming the tube to operating temperature faster. Neon glows bright red or reddish orange when lit. When argon or argon/helium is used, a tiny droplet of mercury is added. Argon by itself is very dim pale lavender when lit,

pos: Diamond anvil cell Even after solidification, noble gases provide quasihydrostatic environments. Argon is used for experiments involving laser heating because it is chemically insulating. Since it condenses at a temperature above that of liquid nitrogen, it can be loaded cryogenically. Helium and neon have low X-ray scattering factors and are thus used for collecting X-ray diffraction data. Helium and neon also have low shear moduli; minimizing strain on the sample. These two noble gases do not condense above that of liquid nitrogen and cannot be loaded cryogenically. Instead, a high-pressure gas loading system has been developed that employs a gas compression method. In

pos: Fluorine gases, krypton forms a difluoride, and radon and fluorine generate a solid suspected to be radon difluoride. Binary fluorides of lighter noble gases are exceptionally unstable: argon and hydrogen fluoride combine under extreme conditions to give argon fluorohydride. Helium and neon have no long-lived fluorides, and no neon fluoride has ever been observed; helium fluorohydride has been detected for milliseconds at high pressures and low temperatures. The carbon–fluorine bond is organic chemistry's strongest, and gives stability to organofluorines. It is almost non-existent in nature, but is used in artificial compounds. Research in this area is usually driven by commercial applications;

pos: Argon compounds to AlB structure. Argon compounds Argon compounds, the chemical compounds that contain the element argon, are rarely encountered due to the inertness of the argon atom. However, compounds of argon have been detected in inert gas matrix isolation, cold gases, and plasmas, and molecular ions containing argon have been made and also detected in space. One solid interstitial compound of argon, ArC is stable at room temperature. ArC was discovered by CSIRO. Argon ionises at 15.76 eV, which is higher than hydrogen, but lower than helium, neon or fluorine. Molecules containing argon can be van der Waals molecules held together

pos: Argon compounds Argon compounds Argon compounds, the chemical compounds that contain the element argon, are rarely encountered due to the inertness of the argon atom. However, compounds of argon have been detected in inert gas matrix isolation, cold gases, and plasmas, and molecular ions containing argon have been made and also detected in space. One solid interstitial compound of argon, ArC is stable at room temperature. ArC was discovered by CSIRO. Argon ionises at 15.76 eV, which is higher than hydrogen, but lower than helium, neon or fluorine. Molecules containing argon can be van der Waals molecules held together very weakly by

pos: Nonmetal No normal compounds of helium have so far been synthesised. Neon has a density of 0.9002 × 10 g/cm, liquifies at −245.95 °C, and solidifies at −248.45 °C. It has the narrowest liquid range of any element and, in liquid form, has over 40 times the refrigerating capacity of liquid helium and three times that of liquid hydrogen. Neon has a very high ionisation energy (2080.7 kJ/mol), low electron affinity (estimated at −120 kJ/mol), and very high electronegativity (4.84 AR). It is the least reactive of the noble gases; no normal compounds of neon have so far been synthesised. Argon

pos: Chemically inert nitrogen, or helium are commonly used in chemical reaction chambers and in storage containers for oxygen-sensitive or water-sensitive substances, to prevent unwanted reactions of these substances with oxygen or water. Argon is widely used in fluorescence tubes and low energy light bulbs. Argon gas helps to protect the metal filament inside the bulb from reacting with oxygen and corroding the filament under high temperature. Neon is used in making advertising signs. Neon gas in a vacuum tube glows bright red in colour when electricity is passed through. Different coloured neon lights can also be made by using other gases. Helium

pos: Buffer gas Buffer gas A buffer gas is an inert or nonflammable gas. In the Earth's atmosphere, nitrogen acts as a buffer gas. A buffer gas adds pressure to a system and controls the speed of combustion with any oxygen present. Any inert gas such as helium, neon, or argon will serve as a buffer gas. Buffer gases are commonly used in many applications from high pressure discharge lamps to reduce line width of microwave transitions in alkali atoms. A buffer gas usually consists of atomically inert gases such as helium, argon, and nitrogen which are the primary gases used. Krypton, neon,

pos: Monatomic gas helium, neon, argon, krypton, xenon and radon. Noble gases have a full outer valence shell making them rather non-reactive species. While these elements have been described historically as completely inert, chemical compounds have been synthesized with all but neon and helium. When grouped together with the homonuclear diatomic gases such as nitrogen (N), the noble gases are called "elemental gases" or "molecular gases" to distinguish them from molecules that are also chemical compounds. Monatomic hydrogen comprises about 75% of the elemental mass of the universe. The motion of a monatomic gas is translation (electronic excitation is not important at room

pos: Noble gas to be retained. Neon, argon, krypton, and xenon also form clathrate hydrates, where the noble gas is trapped in ice. Noble gases can form endohedral fullerene compounds, in which the noble gas atom is trapped inside a fullerene molecule. In 1993, it was discovered that when , a spherical molecule consisting of 60 carbon atoms, is exposed to noble gases at high pressure, complexes such as can be formed (the "@" notation indicates He is contained inside but not covalently bound to it). As of 2008, endohedral complexes with helium, neon, argon, krypton, and xenon have been obtained. These compounds

pos: Trivial name spectrum of the sun (it is not known why the suffix "-ium", which is used for metals, was chosen). The other noble gases are neon ("new"), argon ("slow, lazy"), krypton ("hidden"), xenon ("stranger"), and radon ("from radium"). Many more elements have been given names that have little or nothing to do with their properties. Elements have been named for celestial bodies (helium, selenium, tellurium, for the sun, moon, and earth; cerium and palladium for Ceres and Pallas, two asteroids). They have been named for mythological figures, including Titans in general (titanium) and Prometheus in particular (promethium); Roman and Greek gods

pos: Noble gas in the United States alone. For large-scale use, helium is extracted by fractional distillation from natural gas, which can contain up to 7% helium. Neon, argon, krypton, and xenon are obtained from air using the methods of liquefaction of gases, to convert elements to a liquid state, and fractional distillation, to separate mixtures into component parts. Helium is typically produced by separating it from natural gas, and radon is isolated from the radioactive decay of radium compounds. The prices of the noble gases are influenced by their natural abundance, with argon being the cheapest and xenon the most expensive. As

pos: Noble gas noble gases show extremely low chemical reactivity; consequently, only a few hundred noble gas compounds have been formed. Neutral compounds in which helium and neon are involved in chemical bonds have not been formed (although there is some theoretical evidence for a few helium compounds), while xenon, krypton, and argon have shown only minor reactivity. The reactivity follows the order Ne < He < Ar < Kr < Xe < Rn. In 1933, Linus Pauling predicted that the heavier noble gases could form compounds with fluorine and oxygen. He predicted the existence of krypton hexafluoride () and xenon hexafluoride (),

pos: Inhalational anaesthetic a more difficult problem to pick apart." The possibility of anaesthesia by the inert gas argon in particular (even at 10 to 15 bar) suggests that the mechanism of action of volatile anaesthetics is an effect best described by physical chemistry, and not a chemical bonding action. However, the agent may bind to a receptor with a weak interaction . A physical interaction such as swelling of nerve cell membranes from gas solution in the lipid bilayer may be operative. Notably, the gases hydrogen, helium, and neon have not been found to have anaesthetic properties at any pressure. Helium at

pos: Noble gas is considered to be "full", giving them little tendency to participate in chemical reactions, and it has been possible to prepare only a few hundred noble gas compounds. The melting and boiling points for a given noble gas are close together, differing by less than ; that is, they are liquids over only a small temperature range. Neon, argon, krypton, and xenon are obtained from air in an air separation unit using the methods of liquefaction of gases and fractional distillation. Helium is sourced from natural gas fields which have high concentrations of helium in the natural gas, using cryogenic

pos: William Ramsay William Ramsay Sir William Ramsay, (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous elements in air" (along with his collaborator, John William Strutt, 3rd Baron Rayleigh, who received the Nobel Prize in Physics that same year for their discovery of argon). After the two men identified argon, Ramsay investigated other atmospheric gases. His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section

pos: William Ramsay William Ramsay Sir William Ramsay, (; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous elements in air" (along with his collaborator, John William Strutt, 3rd Baron Rayleigh, who received the Nobel Prize in Physics that same year for their discovery of argon). After the two men identified argon, Ramsay investigated other atmospheric gases. His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section

pos: El Tatio Carbon dioxide is the most important fumarole gas, followed by hydrogen sulfide. The amount of water relative to these two gases is variable, probably due to condensation of water in the ground. Additional components include argon, helium, hydrogen, methane, neon, nitrogen and oxygen. Characteristically for fumarole gases on convergent plate boundaries, much of this nitrogen is non-atmospheric, although atmospheric air is also involved in generating the chemistry of the El Tatio fumarole gases. Opal is the most important component of sinter associated with hot springs; halite, sylvite and realgar are less common. This dominance of opal is because usually conditions

pos: Noble gas excimer lasers. In addition to the compounds where a noble gas atom is involved in a covalent bond, noble gases also form non-covalent compounds. The clathrates, first described in 1949, consist of a noble gas atom trapped within cavities of crystal lattices of certain organic and inorganic substances. The essential condition for their formation is that the guest (noble gas) atoms must be of appropriate size to fit in the cavities of the host crystal lattice. For instance, argon, krypton, and xenon form clathrates with hydroquinone, but helium and neon do not because they are too small or insufficiently polarizable

pos: Periodic table values and electron affinity values, and is not too far from the electronegativity trend, even though hydrogen cannot show the tetravalence characteristic of the heavier group 14 elements. Finally, hydrogen is sometimes placed separately from any group; this is based on its general properties being different from those of the elements in any other group. The other period 1 element, helium, is sometimes placed separately from any group as well. The property that distinguishes helium from the rest of the noble gases (even though the extraordinary inertness of helium is extremely close to that of neon and argon) is that

pos: Large Plasma Device simple without the problems associated with hotter (e.g. fusion-level) plasmas, while still providing a useful environment in which to do research. The typical operational parameters are: In principle, a plasma may be generated from any kind of gas, but inert gases are typically used to prevent the plasma from destroying the coating on the barium oxide cathode. Examples of gases used are helium, argon, nitrogen and neon. Hydrogen is sometimes used for short periods of time. Multiple gases can also be mixed in varying ratios within the chamber to produce multi-species plasmas. At these parameters, the ion Larmor radius is

pos: Morris Travers College, where he began to work with Sir William Ramsay. Travers helped Ramsay to determine the properties of the newly discovered gases argon and helium. They also heated minerals and meteorites in the search for further gases, but found none. Then in 1898 they obtained a large quantity of liquid air and subjected it to fractional distillation. Spectral analysis of the least volatile fraction revealed the presence of krypton. They examined the argon fraction for a constituent of lower boiling point, and discovered neon. Finally xenon, occurring as an even less volatile companion to krypton, was identified spectroscopically. He knew

pos: Nonmetal nonmetals tend to form predominately covalent compounds with metals. Six nonmetals are categorised as noble gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). In periodic table terms they occupy the outermost right column. They are called "noble gases" in light of their characteristically very low chemical reactivity. They have very similar properties, all being colorless, odorless, and nonflammable. With their closed valence shells the noble gases have feeble interatomic forces of attraction resulting in very low melting and boiling points. That is why they are all gases under standard conditions, even those

pos: Atom on Earth. Transuranic elements have radioactive lifetimes shorter than the current age of the Earth and thus identifiable quantities of these elements have long since decayed, with the exception of traces of plutonium-244 possibly deposited by cosmic dust. Natural deposits of plutonium and neptunium are produced by neutron capture in uranium ore. The Earth contains approximately atoms. Although small numbers of independent atoms of noble gases exist, such as argon, neon, and helium, 99% of the atmosphere is bound in the form of molecules, including carbon dioxide and diatomic oxygen and nitrogen. At the surface of the Earth, an overwhelming

pos: Nonmetal Nonmetal In chemistry, a nonmetal (or non-metal) is a chemical element that mostly lacks metallic attributes. Physically, nonmetals tend to have relatively low melting and boiling points, and densities, are mostly brittle if solid, and are usually poor conductors of heat and electricity; chemically, they tend to have relatively high ionization energy, electron affinity, and electronegativity values, and gain or share electrons when they react with other elements or compounds. Seventeen elements are generally classified as nonmetals; most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine), and a few

pos: Chemically inert gas is mainly used to fill hot air and party balloons. Balloons filled with it float upwards and this phenomenon is achieved as helium gas is less dense than air Chemically inert In chemistry, the term chemically inert is used to describe a substance that is not chemically reactive. Most Group 8 or 18 elements that appear in the last column of the periodic table (Helium, Neon, Argon, Krypton, Xenon and Radon) are classified as inert (or unreactive). These elements are stable in their naturally occurring form (gaseous form) and they are called inert gases. The noble gases were previously

pos: Diamond anvil cell a 4:1 methanol-ethanol mixture. Sodium chloride is easy to load and is used for high-temperature experiments because it acts as a good thermal insulator. The methanol-ethanol mixture displays good hydrostaticity to about 10 GPa and with the addition of a small amount of water can be extended to about 15 GPa. For pressure experiments that exceed 10 GPa, noble gases are preferred. The extended hydrostaticity greatly reduces the pressure gradient in samples at high pressure. Noble gases, such as helium, neon, and argon are optically transparent, thermally insulating, have small X-ray scattering factors and have good hydrostaticity at high pressures.

pos: History of chemistry known only in the solar spectrum. In his book "The Gases of the Atmosphere" (1896), Ramsay showed that the positions of helium and argon in the periodic table of elements indicated that at least three more noble gases might exist. In 1898 Ramsay and the British chemist Morris W. Travers isolated these elements—called neon, krypton, and xenon—from air brought to a liquid state at low temperature and high pressure. Sir William Ramsay worked with Frederick Soddy to demonstrate, in 1903, that alpha particles (helium nuclei) were continually produced during the radioactive decay of a sample of radium. Ramsay was awarded

pos: Endohedral fullerene these conditions about one out of every 650,000 C cages was doped with a helium atom. The formation of endohedral complexes with helium, neon, argon, krypton and xenon as well as numerous adducts of the He@C compound was also demonstrated with pressures of 3 kbars and incorporation of up to 0.1% of the noble gases. While noble gases are chemically very inert and commonly exist as individual atoms, this is not the case for nitrogen and phosphorus and so the formation of the endohedral complexes N@C, N@C and P@C is more surprising. The nitrogen atom is in its electronic initial

pos: William R. Bennett Jr. and Ali Javan co-invented the first gas laser (the helium-neon laser) at Bell Laboratories in Murray Hill, New Jersey. He discovered the argon ion laser, was first to observe spectral hole burning effects in gas lasers, and created a theory of hole burning effects on laser oscillation. He was co-discoverer of lasers using electron impact excitation in each of the noble gases, dissociative excitation transfer in the neon-oxygen laser (the first chemical laser), and collision excitation in several metal vapor lasers. He was one of the first to incorporate the use of computers to teach physics and, with his daughter

pos: Laser pumping is common in gas lasers. For example, in the helium–neon laser the electrons from the discharge collide with the helium atoms, exciting them. The excited helium atoms then collide with neon atoms, transferring energy. This allows an inverse population of neon atoms to build up. Electric current is typically used to pump laser diodes and semiconductor crystal lasers (for example germanium) Electron beams pump free electron lasers and some excimer lasers. Gas dynamic lasers are constructed using the supersonic flow of gases, such as carbon dioxide, to excite the molecules past threshold. The gas is pressurized and then heated to

pos: Diatomic molecule 1 bar and 25 °C) are the gases hydrogen (H), nitrogen (N), oxygen (O), fluorine (F), and chlorine (Cl). The noble gases (helium, neon, argon, krypton, xenon, and radon) are also gases at STP, but they are monatomic. The homonuclear diatomic gases and noble gases together are called "elemental gases" or "molecular gases", to distinguish them from other gases that are chemical compounds. At slightly elevated temperatures, the halogens bromine (Br) and iodine (I) also form diatomic gases. All halogens have been observed as diatomic molecules, except for astatine, which is uncertain. The mnemonics BrINClHOF, pronounced "Brinklehof", and HONClBrIF, pronounced

pos: Noble gas compound Noble gas compound Noble gas compounds are chemical compounds that include an element from the noble gases, group 18 of the periodic table. Although the noble gases are generally unreactive elements, many such compounds have been observed, particularly involving the element xenon. From the standpoint of chemistry, the noble gases may be divided into two groups: the relatively reactive krypton (ionisation energy 14.0 eV), xenon (12.1 eV), and radon (10.7 eV) on one side, and the very unreactive argon (15.8 eV), neon (21.6 eV), and helium (24.6 eV) on the other. Consistent with this classification, Kr, Xe, and Rn form

pos: Gas see list of states of matter. The only chemical elements that are stable diatomic homonuclear molecules at STP are hydrogen (H), nitrogen (N), oxygen (O), and two halogens: fluorine (F) and chlorine (Cl). When grouped together with the monatomic noble gases – helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) – these gases are called "elemental gases". The word "gas" was first used by the early 17th-century Flemish chemist Jan Baptist van Helmont. He identified carbon dioxide, the first known gas other than air. Van Helmont's word appears to have been simply a phonetic transcription

pos: Plasma arc welding outer shielding ring of the torch at comparatively higher flow rates. Most of the materials can be welded with argon, helium, argon+hydrogen and argon+helium, as inert gases or gas mixtures. Argon is very commonly used. Helium is preferred where a broad heat input pattern and flatter cover pass is desired without key hole mode weld. A mixture of argon and hydrogen supplies heat energy higher than when only argon is used and thus permits keyhole mode welds in nickel base alloys, copper base alloys and stainless steels. For cutting purposes a mixture of argon and hydrogen (10-30%) or that of

pos: Neon lighting monopoly held in the US by his company, Claude Neon Lights, for neon signs through the early 1930s. Claude's patents envisioned the use of gases such as argon and mercury vapor to create different colors beyond those produced by neon. In the 1920s, fluorescent glasses and coatings were developed to further expand the range of colors and effects for tubes with argon gas or argon-neon mixtures; generally, the fluorescent coatings are used with an argon/mercury-vapor mixture, which emits ultraviolet light that activates the fluorescent coatings. By the 1930s, the colors from combinations of neon tube lights had become satisfactory for

pos: Sorption pump down while the others are still hot. When the first pump has reached its ultimate pressure it is closed off and the next pump is cooled down. Final pressures are in the 10 mbar region. What is left is mainly helium because it is almost not pumped at all. The final pressure almost equals the partial pressure of helium in air. A sorption pump does pump all gases effectively with the exception of hydrogen, helium and neon which do not condensate at liquid nitrogen temperatures and are not efficiently adsorbed by the molecular sieves because of their small molecular size.

pos: Inert gas asphyxiation as an option. In March 2018, Oklahoma Attorney General Mike Hunter and Corrections Director Joe M. Allbaugh announced a switch to nitrogen gas as the primary method of execution. When humans breathe in an asphyxiant gas, such as pure nitrogen, helium, neon, argon, sulfur hexafluoride, methane, or any other physiologically inert gas(es), they exhale carbon dioxide without re-supplying oxygen. Physiologically inert gases (those that have no toxic effect, but merely dilute oxygen) are generally free of odor and taste. As such, the human subject detects little abnormal sensation as the oxygen level falls. This leads to asphyxiation (death from lack

pos: Nitrogen for almost all the transition metals, accounting for several hundred compounds. They are normally prepared by three methods: Occasionally the N≡N bond may be formed directly within a metal complex, for example by directly reacting coordinated ammonia (NH) with nitrous acid (HNO), but this is not generally applicable. Most dinitrogen complexes have colours within the range white-yellow-orange-red-brown; a few exceptions are known, such as the blue [{Ti("η"-CH)}-(N)]. Nitrogen bonds to almost all the elements in the periodic table except the first three noble gases, helium, neon, and argon, and some of the very short-lived elements after bismuth, creating an immense

pos: Neon of water. The familiar Pauling electronegativity scale relies upon chemical bond energies, but such values have obviously not been measured for inert helium and neon. The Allen electronegativity scale, which relies only upon (measurable) atomic energies, identifies neon as the most electronegative element, closely followed by fluorine and helium. Neon is often used in signs and produces an unmistakable bright reddish-orange light. Although tube lights with other colors are often called "neon", they use different noble gases or varied colors of fluorescent lighting. Neon is used in vacuum tubes, high-voltage indicators, lightning arresters, wavemeter tubes, television tubes, and helium–neon lasers.

pos: Electron capture ionization constant on a regular basis. Fragmentation in ECI has been studied by tandem mass spectrometry. The technique can be used with gas chromatography-mass spectrometry. An electron capture detector most often uses a radioactive source to generate electrons used for ionization. Some examples of radioactive isotopes used are H, Ni, Kr, and Sr. The gas in the detector chamber is ionized by the radiation particles. Nitrogen, argon and helium are common carrier gases used in the ECD. Argon and helium need to be combined with another gas, such as methane, in order to prevent immediate conversion into metastable ions. The combination

pos: Cryogenic Low-Energy Astrophysics with Neon cosmic and radiation background. Neon has been studied as a clear, dense, low-background scintilator. CLEAN can use neon or argon and plans runs with both to study nuclear mass dependence of any WIMP signals. The MiniCLEAN detector will operate with argon in 2014. It will have 500 kg of noble cryogen in a spherical steel vessel with 92 PMTs shielded in a water tank with muon rejection. Cryogenic Low-Energy Astrophysics with Neon The Cryogenic Low-Energy Astrophysics with Noble liquids (CLEAN) experiment by the DEAP/CLEAN collaboration is searching for dark matter using noble gases at the SNOLAB underground facility. CLEAN has

pos: Gas metal arc welding eliminates slag, the hard residue from the flux that builds up after welding and must be chipped off to reveal the completed weld. The choice of a shielding gas depends on several factors, most importantly the type of material being welded and the process variation being used. Pure inert gases such as argon and helium are only used for nonferrous welding; with steel they do not provide adequate weld penetration (argon) or cause an erratic arc and encourage spatter (with helium). Pure carbon dioxide, on the other hand, allows for deep penetration welds but encourages oxide formation, which adversely affects

pos: Gas metal arc welding for welding steels. Other mixtures add a small amount of helium to argon-oxygen combinations, these mixtures are claimed to allow higher arc voltages and welding speed. Helium also sometimes serves as the base gas, with small amounts of argon and carbon dioxide added. However, because it is less dense than air, helium is less effective at shielding the weld than argon—which is denser than air. It also can lead to arc stability and penetration issues, and increased spatter, due to its much more energetic arc plasma. Helium is also substantially more expensive than other shielding gases. Other specialized and often

pos: Helium–neon laser Bell Telephone Laboratories in 1962, 18 months after the pioneering demonstration at the same laboratory of the first continuous infrared HeNe gas laser in December 1960. The gain medium of the laser, as suggested by its name, is a mixture of helium and neon gases, in approximately a 10:1 ratio, contained at low pressure in a glass envelope. The gas mixture is mostly helium, so that helium atoms can be excited. The excited helium atoms collide with neon atoms, exciting some of them to the state that radiates 632.8 nm. Without helium, the neon atoms would be excited mostly to

pos: Compounds of oxygen pyrimidines of RNA and DNA, and in bones as calcium phosphate and hydroxylapatite. Compounds of oxygen The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: − (superoxides), − (ozonides), 0 (elemental, hypofluorous acid), + (dioxygenyl), +1 (dioxygen difluoride), and +2 (oxygen difluoride). Oxygen is reactive and will form oxides with all other elements except the noble gases helium, neon, argon, and krypton. Water () is the oxide of hydrogen and most familiar

pos: Noble gas a mineral. In 1902, having accepted the evidence for the elements helium and argon, Dmitri Mendeleev included these noble gases as group 0 in his arrangement of the elements, which would later become the periodic table. Ramsay continued his search for these gases using the method of fractional distillation to separate liquid air into several components. In 1898, he discovered the elements krypton, neon, and xenon, and named them after the Greek words (, "hidden"), (, "new"), and (, "stranger"), respectively. Radon was first identified in 1898 by Friedrich Ernst Dorn, and was named "radium emanation", but was not considered

pos: United Minerals Group in cement, concrete, autoclaved aerated concrete, and other construction mixes. Apart from Ukraine, ASM, including microspheres, are delivered to Belarus, the Netherlands, the USA, Argentina, Germany, Portugal, Spain, the Czech Republic, Slovenia, Azerbaijan and the Middle East. Key indicators in this area: UMG’s new business direction was launched in August 2015. Products include rare (neon, krypton, xenon, helium) and technical (argon, nitrogen, oxygen) gases. Resource base: Metinvest Holding enterprises, Chinese metal companies. Key consumers: manufacturers of electronics, laser, lighting equipment, medical and space sectors etc. Key indicators in this area: This business is represented by UMG TRADING and UMG AGRO.

pos: Alice (spacecraft instrument) type photocathodes. It detects in the extreme and far ultraviolet spectrum, from wavelengths of light. Alice is intended, among its capabilities, to detect ultraviolet signatures of noble (aka inert) gases including helium, neon, argon, and krypton. Alice should also be able to detect water, carbon monoxide, and carbon dioxide in the ultraviolet. ALICE was built and operated by the Southwest Research Institute for NASA's Jet Propulsion Laboratory. In August 2018, NASA confirmed, based on results by "Alice" on the "New Horizons" spacecraft, the detection of a "hydrogen wall" at the outer edges of the Solar System that was first detected

pos: Compounds of oxygen Compounds of oxygen The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: − (superoxides), − (ozonides), 0 (elemental, hypofluorous acid), + (dioxygenyl), +1 (dioxygen difluoride), and +2 (oxygen difluoride). Oxygen is reactive and will form oxides with all other elements except the noble gases helium, neon, argon, and krypton. Water () is the oxide of hydrogen and most familiar oxygen compound. Its bulk properties partly result from the interaction of its component

pos: Nitrogen narcosis results from breathing gases under elevated pressure, and may be classified by the principal gas involved. The noble gases, except helium and probably neon, as well as nitrogen, oxygen and hydrogen cause a decrement in mental function, but their effect on psychomotor function (processes affecting the coordination of sensory or cognitive processes and motor activity) varies widely. The effects of carbon dioxide consistently result in a diminution of mental and psychomotor function. The noble gases argon, krypton, and xenon are more narcotic than nitrogen at a given pressure, and xenon has so much anesthetic activity that it is a usable

pos: Chemically inert Chemically inert In chemistry, the term chemically inert is used to describe a substance that is not chemically reactive. Most Group 8 or 18 elements that appear in the last column of the periodic table (Helium, Neon, Argon, Krypton, Xenon and Radon) are classified as inert (or unreactive). These elements are stable in their naturally occurring form (gaseous form) and they are called inert gases. The noble gases were previously known as "inert gases" because of their perceived lack of participation in any chemical reactions. The reason for this is that their outermost electron shells (valence shells) are completely filled,

pos: Cryogenic Low-Energy Astrophysics with Neon Cryogenic Low-Energy Astrophysics with Neon The Cryogenic Low-Energy Astrophysics with Noble liquids (CLEAN) experiment by the DEAP/CLEAN collaboration is searching for dark matter using noble gases at the SNOLAB underground facility. CLEAN has studied neon and argon in the MicroCLEAN prototype, and running the MiniCLEAN detector to test a multi-ton design. Dark matter searches in isolated noble gas scintilators with xenon and argon have set limits on WIMP interactions, such as recent cross sections from LUX and XENON. Particles scattering in the target emit photons detected by PMTs, identified via pulse shape discrimination developed on DEAP results. Shielding reduces the

pos: Volcanic gas gases), nitrogen, argon, helium, neon, methane, carbon monoxide and hydrogen. Other compounds detected in volcanic gases are oxygen (meteoric), hydrogen chloride, hydrogen fluoride, hydrogen bromide, nitrogen oxide (NO), sulfur hexafluoride, carbonyl sulfide, and organic compounds. Exotic trace compounds include mercury, halocarbons (including CFCs), and halogen oxide radicals. The abundance of gases varies considerably from volcano to volcano, with volcanic activity and with tectonic setting. Water vapour is consistently the most abundant volcanic gas, normally comprising more than 60% of total emissions. Carbon dioxide typically accounts for 10 to 40% of emissions. Volcanoes located at convergent plate boundaries emit more water

neg: Argonium helium or neon) the argon ion reacts with molecular hydrogen, but for helium and neon ions, they will strip an electron from a hydrogen molecule. Artificial ArH made from earthly argon contains mostly the isotope Ar rather than the cosmically abundant Ar. Artificially it is made by an electric discharge through an argon-hydrogen mixture. Brault and Davis were the first to detect the molecule using infrared spectroscopy to observe vibration-rotation bands. The UV spectrum has two absorption points resulting in the ion breaking up. The 11.2 eV conversion to the BΠ state has a low dipole and so does not

neg: The Kingswinford School School joined the Windsor Academy Trust (WAT), run by Windsor High School to become part of a Multi Academy Trust (MAT). The school frequently receives financial grants from the government to help its funds and upkeeping. The school is run by the head teacher, Thomas Macdonald. There is about 51 staff operating in the school and 914 students. There are roughly 180 students per year group and 220 per house (Krypton, Neon, Argon and Helium). The current house leaders are: Krypton – James Wilkes, Neon - Lynda Wise, Argon – Jill Edgington and Helium - Nathan Tromans. The school is

neg: X-ray fluorescence speeds in order to cope with the very high photon count rates that can be obtained. In addition, they need sufficient energy resolution to allow filtering-out of background noise and spurious photons from the primary beam or from crystal fluorescence. There are four common types of detector: Gas flow proportional counters are used mainly for detection of longer wavelengths. Gas flows through it continuously. Where there are multiple detectors, the gas is passed through them in series, then led to waste. The gas is usually 90% argon, 10% methane ("P10"), although the argon may be replaced with neon or helium

neg: Chemistry: A Volatile History lines which Lockyer had observed: helium. Prior to this, Ramsay had already isolated a new gas from the atmosphere; argon, with an atomic weight of 40. A problem now arose – Mendeleev had not left any gaps which were suitable for either of these two new elements, which led Ramsay to conclude an entire group was missing from the periodic table – only two of whose members were now known to exist, helium and argon. Ramsey successfully discovered all the other stable elements in the group which he named neon (Greek for new), krypton (Greek for hidden) and xenon (Greek

neg: Helium compounds can be increased by pressing it. Other inert gas impurity helium condensates can also be made from a gas beam into superfluid helium. [Ne]/[He] decomposes at 8.5 K with release of heat and formation of solid neon. Its composition approximates NeHe. [Ar]/[He] contains 40–60 helium atoms per argon atom. [Kr]/[He] contains 40–60 helium atoms per krypton atom and is stable up to 20 K. [Xe]/[He] contains 40–60 helium atoms per xenon atom. [N]/[He] contains 12—17 He atoms per N molecule. It is stable up to 13 K [N]/[Ne]/[He] Formed from a gas beam generated from a radio-frequency electric discharge in

neg: Helium compounds argon and then form a cluster ion when the rest of the droplet evaporates. NeHe can be made by ultraviolet photoionisation. Clusters only contain one neon atom. The number of helium atoms n can vary from 1 to 23, but NeHe and NeHe are more likely to be observed. Doubly charged ions of helium with noble gas atoms also exist including ArHe, KrHe, and XeHe. Various metal-helium ions are known. Alkali metal helide ions are known for all the alkalis. The molecule ground state for the diatomic ions is in the XΣ state. The bond length gets bigger as the

neg: Gas laser in LASIK eye surgery. Commonly used excimer molecules include F (fluorine, emitting at 157 nm), and (ArF [193 nm], KrCl [222 nm], KrF [248 nm], XeCl [308 nm], and XeF [351 nm]). Argon-ion lasers emit light in the range 351–528.7 nm. Depending on the optics and the laser tube a different number of lines is usable but the most commonly used lines are 458 nm, 488 nm and 514.5 nm. Metal-vapor lasers are gas lasers that typically generate ultraviolet wavelengths. Helium-silver (HeAg) 224 nm neon-copper (NeCu) 248 nm and helium-cadmium (HeCd) 325 nm are three examples. These lasers have particularly

neg: Halogenation most common organohalides in nature. Their formation is catalyzed by the enzyme bromoperoxidase which utilizes bromide in combination with oxygen as an oxidant. The oceans are estimated to release 1–2 million tons of bromoform and 56,000 tons of bromomethane annually. Iodine is the least reactive halogen and is reluctant to react with most organic compounds. The addition of iodine to alkenes is the basis of the analytical method called the iodine number, a measure of the degree of unsaturation for fats. The iodoform reaction involves degradation of methyl ketones. All elements aside from argon, neon, and helium form fluorides by

neg: Ion laser use in underwater communications because seawater is quite transparent in this range of wavelengths. Common argon and krypton lasers are capable of emitting continuous-wave (CW) output of several milliwatts to tens of watts. Their tubes are usually made from nickel end bells, kovar metal-to-ceramic seals, beryllium oxide ceramics, or tungsten disks mounted on a copper heat spreader in a ceramic liner. The earliest tubes were simple quartz, then followed by quartz with graphite disks. In comparison with the helium–neon lasers, which require just a few milliamperes of input current, the current used for pumping the krypton laser is several amperes,

neg: Neon compounds crystals of ammonium iron formate (NHFe(HCOO)) and ammonium nickel formate (NHNi(HCOO)) at 1.5 GPa to yield Ne•NHFe(HCOO) and Ne•NHNi(HCOO). The neon atoms become trapped in a cage of five metal triformate units. The windows in the cages are blocked by ammonium ions. Argon does not undergo this, probably as its atoms are too big. Ionic molecules can include neon, such as the clusters where "m" goes from 1 to 7 and "n" from 1 to over 20. HeNe (helium neide) has a relatively strong covalent bond. The charge is distributed across both atoms. When metals are evaporated into a thin

neg: Penning mixture excited state of the noble gas. The energy of the excited, but neutral, noble gas atoms then can ionize the quench gas particles by energy transfer via collisions; known as the Penning effect. A very common Penning mixture of about 98–99.5% of neon with 0.5–2% of argon is used in some neon lamps, especially those rated at 110 volts. The mixture is easier to ionize than either neon or argon alone, and lowers the striking voltage at which the tube becomes conductive and starts producing light. The optimal level of argon is about 0.25%, but some of it gets adsorbed

neg: Helium compounds 1. Many different HeKr exist with n=1 to 17 at least. HeKr and HeKr also exist for many values of n. HeKr and HeKr ions are commons. These singly charged cluster ions can be made from krypton in helium nanodroplets subject to vacuum ultraviolet radiation. The Ar argon ion can form many different sized clusters with helium ranging from HeAr to HeAr, but the most common clusters are HeAr and smaller. These clusters are made by capturing an argon atom in a liquid helium nanodroplet, and then ionising with high speed electrons. He is formed, which can transfer charge to

neg: Foundation Seamounts the neon and helium isotope ratios suggesting that the hotspot is a mantle plume, which is interacting with the spreading ridge. The Foundation hotspot is considerably weaker than many other hotspots such as the Society hotspot or the Hawaii hotspot, and its volcanoes were constructed in shorter timespans than the Hawaiian ones. Because an age progression was not found at first (Macdonald seamount is active in its own right), a "hot line" origin was proposed at first; argon-argon dating performed later on rocks dredged from the seamounts has demonstrated clearly age progressive volcanism. The plume may be located either directly

neg: Compounds of fluorine state is −1. It differs from this value in elemental fluorine, where the atoms are bonded to each other and thus at oxidation state 0, and a few polyatomic ions: the very unstable anions and with intermediate oxidation states exist at very low temperatures, decomposing at around 40 K. Also, the cation and a few related species have been predicted to be stable. Fluorine forms compounds with all elements except neon and helium. In particular, it forms binary compounds, named fluorides, with all said elements except argon. All of the elements up to einsteinium, element 99, have been checked except

neg: Noble gas compound with a krypton-oxygen bond. A krypton-nitrogen bond is found in the cation [HC≡N–Kr–F], produced by the reaction of with [HC≡NH][AsF] below −50 °C. The discovery of HArF was announced in 2000. The compound can exist in low temperature argon matrices for experimental studies, and it has also been studied computationally. Argon hydride ion was obtained in the 1970s. This molecular ion has also been identified in the Crab nebula, based on the frequency of its light emissions. A neon compound has yet to be described. There is some empirical and theoretical evidence for a few metastable helium compounds which may

neg: Degenerate energy levels experimentally include MOSFET, two-dimensional superlattices of Helium, Neon, Argon, Xenon etc. and surface of liquid Helium. The presence of degenerate energy levels is studied in the cases of particle in a box and two-dimensional harmonic oscillator, which act as useful mathematical models for several real world systems. Consider a free particle in a plane of dimensions formula_24 and formula_25 in a plane of impenetrable walls. The time-independent Schrödinger equation for this system with wave function formula_10 can be written as Degenerate energy levels In quantum mechanics, an energy level is degenerate if it corresponds to two or more different measurable

neg: William Ramsay a short conversation he and Ramsay decided to investigate this. In August Ramsay told Rayleigh he had isolated a new, heavy component of air, which did not appear to have any chemical reactivity. He named this inert gas "argon", from the Greek word meaning "lazy". In the following years, working with Morris Travers, he discovered neon, krypton, and xenon. He also isolated helium, which had only been observed in the spectrum of the sun, and had not previously found on earth. In 1910 he isolated and characterized radon. During 1893-1902 Ramsay also collaborated with Emily Aston, a British chemist, in

neg: Moon has an atmosphere so tenuous as to be nearly vacuum, with a total mass of less than . The surface pressure of this small mass is around 3 × 10 atm (0.3 nPa); it varies with the lunar day. Its sources include outgassing and sputtering, a product of the bombardment of lunar soil by solar wind ions. Elements that have been detected include sodium and potassium, produced by sputtering (also found in the atmospheres of Mercury and Io); helium-4 and neon from the solar wind; and argon-40, radon-222, and polonium-210, outgassed after their creation by radioactive decay within the crust

neg: Biophotonics nm, 501.7 nm, 514.5 nm (multi-line operation possible) - Krypton Ion laser: 350.7 nm, 356.4 nm, 476.2 nm, 482.5 nm, 520.6 nm, 530.9 nm, 568.2 nm, 647.1 nm, 676.4 nm, 752.5 nm, 799.3 nm - Helium–neon laser: 632.8 nm (543.5 nm, 594.1 nm, 611.9 nm) - HeCd lasers: 325 nm, 442 nm Other commercial gas lasers like carbon dioxide (CO2), carbon monoxide, nitrogen, oxygen, xenon-ion, excimer or metal vapor lasers have no or only very minor importance in biophotonics. Major advantage of gas lasers in biophotonics is their fixed wavelength, their perfect beam quality and their low linewidth/high coherence. Argon

neg: Xenon monochloride for states B and C. For helium and krypton, no comparison is available. For neon, only the reaction with first two vibrational levels of B have been documented: XeCl(B; v = 1) + Ne → XeCl(B ; v = 0) + Ne "with rate constant of k=(0.3 to 0.5) cms". For argon, the values of k has been determined for v=33, 60 and 75. Their values, respectively, are (17 ± 5); (31 ± 9) and (43 ± 10) cm. Other authors placed the figure for k between (10 and 15) agreeing on the order of magnitude. The chemical kinetics due

neg: Argon compounds is 5f(δφ) whereas in neon it is 5f7s (the state H compared to Φ). This is because the argon atoms have a larger antibonding interaction with the 7s electron, forcing it into a different subshell. The argonated compound has a stretching frequency of 776 cm compared to 914.8 cm in neon. The argon uranium dioxide molecule is likely UOAr. When beryllium atoms react with oxygen in a solid argon matrix (or beryllia is evaporated into the matrix) ArBeO will be formed, and is observable by its infrared spectrum. The beryllia molecule is strongly polarised, and the argon atom is attracted

neg: Green frequency that is twice that of the incident beam (563.5 THz); in this case corresponding to the wavelength of 532nm ("green"). Other green wavelengths are also available using DPSS technology ranging from 501 nm to 543 nm. Green wavelengths are also available from gas lasers, including the helium–neon laser (543nm), the Argon-ion laser (514nm) and the Krypton-ion laser (521nm and 531nm), as well as liquid dye lasers. Green lasers have a wide variety of applications, including pointing, illumination, surgery, laser light shows, spectroscopy, interferometry, fluorescence, holography, machine vision, non-lethal weapons and bird control. As of mid-2011, direct green laser diodes

neg: Oxygen is composed of three stable isotopes, O, O, and O, with O being the most abundant (99.762% natural abundance). Most O is synthesized at the end of the helium fusion process in massive stars but some is made in the neon burning process. O is primarily made by the burning of hydrogen into helium during the CNO cycle, making it a common isotope in the hydrogen burning zones of stars. Most O is produced when N (made abundant from CNO burning) captures a He nucleus, making O common in the helium-rich zones of evolved, massive stars. Fourteen radioisotopes have been

neg: The Eye of Argon these events were spontaneous, others were officially scheduled. Usually they were held late at night or in the wee hours. Reading "The Eye of Argon" aloud has been made into a game, as described by SF critic Dave Langford in "SFX magazine": "The challenge of death, at SF conventions, is to read "The Eye of Argon" aloud, straight-faced, without choking and falling over. The grandmaster challenge is to read it with a squeaky voice after inhaling helium. What fun we fans have." Strict rules also include not laughing and reading all mistakes exactly as written. Making it through three-quarters of

neg: Shielding gas high ionization potential; the gas can absorb high amount of energy before becoming ionized. Argon is the common shielding gas, widely used as the base for the more specialized gas mixes. Carbon dioxide is the least expensive shielding gas, providing deep penetration, however it negatively affects the stability of the arc and enhances the molten metal's tendency to create droplets (spatter). Carbon dioxide in concentration of 1-2% is commonly used in the mix with argon to reduce the surface tension of the molten metal. Another common blend is 25% carbon dioxide and 75% argon for GMAW. Helium is lighter than

neg: Gas chromatography example, a DID requires helium as the carrier gas. When analyzing gas samples, however, the carrier is sometimes selected based on the sample's matrix, for example, when analyzing a mixture in argon, an argon carrier is preferred, because the argon in the sample does not show up on the chromatogram. Safety and availability can also influence carrier selection, for example, hydrogen is flammable, and high-purity helium can be difficult to obtain in some areas of the world. (See: Helium—occurrence and production.) As a result of helium becoming more scarce, hydrogen is often being substituted for helium as a carrier gas

neg: Gas tungsten arc welding striking an arc with helium gas, and the decreased weld quality associated with a varying arc length. Argon-helium mixtures are also frequently utilized in GTAW, since they can increase control of the heat input while maintaining the benefits of using argon. Normally, the mixtures are made with primarily helium (often about 75% or higher) and a balance of argon. These mixtures increase the speed and quality of the AC welding of aluminum, and also make it easier to strike an arc. Another shielding gas mixture, argon-hydrogen, is used in the mechanized welding of light gauge stainless steel, but because hydrogen

neg: Nuclear fission the smallest of these may range from so small a charge and mass as a proton (Z=1), to as large a fragment as argon (Z=18). The most common small fragments, however, are composed of 90% helium-4 nuclei with more energy than alpha particles from alpha decay (so-called "long range alphas" at ~ 16 MeV), plus helium-6 nuclei, and tritons (the nuclei of tritium). The ternary process is less common, but still ends up producing significant helium-4 and tritium gas buildup in the fuel rods of modern nuclear reactors. The fission of a heavy nucleus requires a total input energy of

neg: Dekatron dot appears at a random cathode; the tube must then be reset to zero state, by driving a negative pulse into the designated starting cathode. The color of the dot depends on the type of gas that is in the tube. Neon-filled tubes display a red-orange dot; argon-filled tubes display a purple dot (and are much dimmer than neon). "Counter" (common-cathode) dekatrons have only one carry/borrow cathode wired to its own socket pin for multistage cascading and the remaining nine cathodes tied together to another pin; therefore they don't need bases with more than 9 pins. "Counter/Selector" (separate-cathode) dekatrons have

neg: Mercury (element) is a common calibration practice. Gaseous mercury is also found in some electron tubes, including ignitrons, thyratrons, and mercury arc rectifiers. It is also used in specialist medical care lamps for skin tanning and disinfection. Gaseous mercury is added to cold cathode argon-filled lamps to increase the ionization and electrical conductivity. An argon-filled lamp without mercury will have dull spots and will fail to light correctly. Lighting containing mercury can be bombarded/oven pumped only once. When added to neon filled tubes the light produced will be inconsistent red/blue spots until the initial burning-in process is completed; eventually it will light

neg: Argon is preferable to the helium that had been used in the preceding five decades, because helium gas escapes through the intermolecular pores in most containers and must be regularly replaced. Argon may be used as the inert gas within Schlenk lines and gloveboxes. Argon is preferred to less expensive nitrogen in cases where nitrogen may react with the reagents or apparatus. Argon may be used as the carrier gas in gas chromatography and in electrospray ionization mass spectrometry; it is the gas of choice for the plasma used in ICP spectroscopy. Argon is preferred for the sputter coating of specimens

neg: Thioxoethenylidene Thioxoethenylidene Thioxoethenylidene (or dicarbon monosulfide), is a reactive heterocumulene molecule with formula CCS. CCS is found in space in large quantities. This includes the Taurus Molecular Cloud in TMC-1, TMC-1c and L1521B. These are likely in young starless molecular cloud cores. By condensing propadienedithione SCCCS or thioxopropadienone OCCCS in solid argon and irradiating with ultraviolet radiation, CCS is formed. Another way is via a glow discharge in a mixture of carbon disulfide and helium. Yet another way is through electron irradiation of sulfur containing heterocycles. CCS and the anion CCS can be formed in solid neon matrices also. CCS can

neg: Breathing arteries to the limbs and abdominal viscera. This reserves the oxygen that is in blood and lungs at the beginning of the dive almost exclusively for the heart and the brain. The diving reflex is an often-used response in animals that routinely need to dive, such as penguins, seals and whales. It is also more effective in very young infants and children than in adults. Inhaled air is by volume 78.08% nitrogen, 20.95% oxygen and small amounts include argon, carbon dioxide, neon, helium, and hydrogen. The gas exhaled is 4% to 5% by volume of carbon dioxide, about a 100

neg: Atomic orbital terms of electron shells and subshells which can each hold a number of electrons determined by the Pauli exclusion principle. Thus the "n" = 1 state can hold one or two electrons, while the "n" = 2 state can hold up to eight electrons in 2s and 2p subshells. In helium, all "n" = 1 states are fully occupied; the same for "n" = 1 and "n" = 2 in neon. In argon the 3s and 3p subshells are similarly fully occupied by eight electrons; quantum mechanics also allows a 3d subshell but this is at higher energy than the

neg: Richard Buckingham King. He was educated at Gresham's School, Holt, and St John's College, Cambridge. After Cambridge, Buckingham's first academic post was at Queen's University, Belfast, where he was an assistant lecturer in Mathematical Physics from 1935 to 1938. In 1938 he published a paper titled 'The classical equation of state of gaseous Helium, Neon and Argon', which proposed a formula which became known as the Buckingham potential. The same year, he took up a new post as Senior 1851 Exhibitioner at University College, London, before serving in the Royal Navy's Admiralty Research Laboratory, Teddington, and in the Mine Design Department at

neg: Buffer gas any contaminants. Contaminants can potentially lodge in the space between the seal and cause metal to metal contact in the compressor, leading to compressor failure (above right). In this case the buffer gas acts in a way much like oil does in an automotive engine’s bearings. Buffer gas A buffer gas is an inert or nonflammable gas. In the Earth's atmosphere, nitrogen acts as a buffer gas. A buffer gas adds pressure to a system and controls the speed of combustion with any oxygen present. Any inert gas such as helium, neon, or argon will serve as a buffer gas.

neg: Industrial gas nitrogen (1772), nitrous oxide (1772) , oxygen (1773) , ammonia (1774), chlorine (1774), methane (1776), hydrogen sulfide (1777), carbon monoxide (1800), hydrogen chloride (1810), acetylene (1836), helium (1868) fluorine (1886), argon (1894), krypton, neon and xenon (1898) Carbon dioxide, hydrogen, nitrous oxide, oxygen, ammonia, chlorine, sulfur dioxide and manufactured fuel gas were already being used during the 19th century, and mainly had uses in food, refrigeration, medicine, and for fuel and gas lighting. For example, carbonated water was being made from 1772 and commercially from 1783, chlorine was first used to bleach textiles in 1785 and nitrous oxide was first

neg: Atomic orbital angular momentum, not primarily because of its relationship with electron wavelength, which appeared in hindsight a dozen years after the Bohr model was proposed. The Bohr model was able to explain the emission and absorption spectra of hydrogen. The energies of electrons in the "n" = 1, 2, 3, etc. states in the Bohr model match those of current physics. However, this did not explain similarities between different atoms, as expressed by the periodic table, such as the fact that helium (two electrons), neon (10 electrons), and argon (18 electrons) exhibit similar chemical inertness. Modern quantum mechanics explains this in

neg: Buckingham potential of state for gaseous helium, neon and argon. As explained in Buckingham's original paper and, e.g., in section 2.2.5 of Jensen's text, the repulsion is due to the interpenetration of the closed electron shells. "There is therefore some justification for choosing the repulsive part (of the potential) as an exponential function". The Buckingham potential has been used extensively in simulations of molecular dynamics. Because the exponential term converges to a constant as formula_2→formula_9, while the formula_10 term diverges, the Buckingham potential becomes attractive as formula_2 becomes small. This may be problematic when dealing with a structure with very short interatomic

neg: Flashtube lighter ones. Helium and neon are far too light to produce an efficient flash. Krypton can be as good as 40% efficient, but requires up to a 70% increase in pressure over xenon to achieve this. Argon can be up to 30% efficient, but requires an even greater pressure-increase. At such high pressures, the voltage drop between the electrodes, formed by the spark streamer, may be greater than the capacitor voltage. These lamps often need a "boost voltage" during the trigger phase, to overcome the extremely high trigger-impedance. Nitrogen, in the form of air, has been used in flashtubes in

neg: Mariner 10 it passed in front of the Sun, and detected whether solar ultraviolet radiation was absorbed at certain wavelengths, which would indicate the presence of gas particles, and therefore an atmosphere. The airglow spectrometer detected extreme ultraviolet radiation emanating from atoms of gaseous hydrogen, helium, carbon, oxygen, neon, and argon. Unlike the occultation spectrometer, it did not require backlighting from the Sun, and could move along with the rotatable scan platform on the spacecraft. The experiment's most important goal was to ascertain whether Mercury had an atmosphere, but would also gather data at Earth and Venus and study the interstellar background

neg: Chemistry elements (helium, neon, argon, krypton, xenon and radon) are composed of lone atoms as their smallest discrete unit, but the other isolated chemical elements consist of either molecules or networks of atoms bonded to each other in some way. Identifiable molecules compose familiar substances such as water, air, and many organic compounds like alcohol, sugar, gasoline, and the various pharmaceuticals. However, not all substances or chemical compounds consist of discrete molecules, and indeed most of the solid substances that make up the solid crust, mantle, and core of the Earth are chemical compounds without molecules. These other types of substances,

neg: Laser pumping all of the noble gas types, including xenon, krypton, argon, neon, and helium, which all emit spectral lines that are very specific to the gas. The output spectrum of an arc lamp is mostly dependent on the gas type, being narrow band spectral lines very similar to a flashlamp operated at low current densities. The output is highest in the near infrared, and are usually used to pump infrared lasers such as Nd:YAG. A laser of a suitable type can be used to pump another laser. The pump laser's narrow spectrum allows it to be closely matched to the absorption

neg: Neon Liquefied neon is commercially used as a cryogenic refrigerant in applications not requiring the lower temperature range attainable with more extreme liquid-helium refrigeration. Neon, as liquid or gas, is relatively expensive – for small quantities, the price of liquid neon can be more than 55 times that of liquid helium. Driving neon's expense is the rarity of neon, which unlike helium, can only be obtained from air. The triple point temperature of neon (24.5561 K) is a defining fixed point in the International Temperature Scale of 1990. Neon Neon is a chemical element with symbol Ne and atomic number 10.