What are neon, argon, xenon and krypton?
"normal atmospheric pressure), other gases such as nitrogen, and noble gases such as argon, krypton, and xenon become anaesthetics. When inhaled at high partial pressures (more than about 4 bar, encountered at depths below about 30 metres in scuba diving), nitrogen begins to act as an anaesthetic agent, causing nitrogen narcosis. However, the minimum alveolar concentration (MAC) for nitrogen is not achieved until pressures of about 20 to 30 atm (bar) are attained. Argon is slightly more than twice as anaesthetic as nitrogen per unit of partial pressure (see argox). Xenon however is a usable anaesthetic at 80% concentration and"
"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,"
"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,"
"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"
"to be isolated. Krypton, neon, and xenon: In 1898, within a period of three weeks, Ramsay and Travers successively separated krypton, neon and xenon from liquid argon by exploiting differences in their boiling points. In 1898, Dorn discovered a radioactive gas resulting from the radioactive decay of radium; Ramsay and Robert Whytlaw-Gray subsequently isolated radon in 1910. Astatine was synthesised in 1940 by Dale R. Corson, Kenneth Ross MacKenzie, and Emilio Segrè. They bombarded bismuth-209 with alpha particles in a cyclotron to produce, after emission of two neutrons, astatine-211. Unless otherwise stated, melting points, boiling points, densities, crystalline structures, ionisation"
"Xenon Xenon is a chemical element with symbol Xe and atomic number 54. It is a colorless, dense, odorless noble gas found 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. Xenon is used in flash lamps and arc lamps, and as a general anesthetic. The first excimer laser design used a xenon dimer molecule (Xe) as the lasing medium, and the earliest laser designs used xenon flash lamps as pumps. Xenon is used to search for"
"Krypton Krypton (from ""the hidden one"") is a chemical element with symbol Kr and atomic number 36. It is a member of group 18 (noble gases) elements. A colorless, odorless, tasteless noble gas, krypton 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. Krypton light has many spectral lines, and krypton plasma is useful in bright, high-powered gas lasers (krypton ion and excimer lasers), each of which resonates and amplifies a single"
"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"
"silicon, and aluminium. By analyzing all three isotopes, the cosmogenic component can be resolved from magmatic neon and nucleogenic neon. This suggests that neon will be a useful tool in determining cosmic exposure ages of surface rocks and meteorites. Similar to xenon, neon content observed in samples of volcanic gases is enriched in Ne and nucleogenic Ne relative to Ne content. The neon isotopic content of these mantle-derived samples represents a non-atmospheric source of neon. The Ne-enriched components are attributed to exotic primordial rare-gas components in the Earth, possibly representing solar neon. Elevated Ne abundances are found in diamonds, further"
"gases neon, krypton, and xenon is the distillation of air using at least two distillation columns. Pure gases can be separated from air by first cooling it until it liquefies, then selectively distilling the components at their various boiling temperatures. The process can produce high purity gases but is energy-intensive. This process was pioneered by Carl von Linde in the early 20th century and is still used today to produce high purity gases. He developed it in the year 1895 after which the process went around seven years as a pure academical process before it was used in industrial applications"
"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"
"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"
"−157.37 °C. It has a high ionisation energy (1350.8 kJ/mol), low electron affinity (estimated at −60 kJ/mol), and high electronegativity (2.94 AR). Krypton can be reacted with fluorine to form the difluoride, KrF. The reaction of with produces an unstable compound, , that contains a krypton-oxygen bond. Xenon has a density of 5.894 × 10 g/cm, liquifies at −161.4 °C, and solidifies at −165.051 °C. It is non-toxic, and belongs to a select group of substances that penetrate the blood–brain barrier, causing mild to full surgical anesthesia when inhaled in high concentrations with oxygen. Xenon has a high ionisation energy"
"the elements krypton and neon. They found xenon in the residue left over from evaporating components of liquid air. Ramsay suggested the name ""xenon"" for this gas from the Greek word ""ξένον"" [xenon], neuter singular form of ""ξένος"" [xenos], meaning 'foreign(er)', 'strange(r)', or 'guest'. In 1902, Ramsay estimated the proportion of xenon in the Earth's atmosphere to be one part in 20 million. During the 1930s, American engineer Harold Edgerton began exploring strobe light technology for high speed photography. This led him to the invention of the xenon flash lamp in which light is generated by passing brief electric current"
"and specific heat. Monatomic gases such as argon, krypton and xenon are often used since (at normal temperatures) they do not carry heat in rotational modes, resulting in a lower heat capacity than poly-atomic gases. Argon has a thermal conductivity 67% that of air, krypton has about half the conductivity of argon. Argon is almost 1% of the atmosphere and isolated at a moderate cost. Krypton and xenon are only trace components of the atmosphere and very expensive. All of these ""noble"" gases are non-toxic, clear, odorless, chemically inert, and commercially available because of their widespread application in industry. Some"
"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"
"matrices, or in supersonic noble gas jets. In theory, radon is more reactive than xenon, and therefore should form chemical bonds more easily than xenon does. However, due to the high radioactivity and short half-life of radon isotopes, only a few fluorides and oxides of radon have been formed in practice. Krypton is less reactive than xenon, but several compounds have been reported with krypton in the oxidation state of +2. Krypton difluoride is the most notable and easily characterized. Under extreme conditions, krypton reacts with fluorine to form KrF according to the following equation: Compounds in which krypton forms"
"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"
"as ""neon lights"". These lights are called after neon but often contain other gases and phosphors, which add various hues to the orange-red color of neon. Xenon is commonly used in xenon arc lamps which, due to their nearly continuous spectrum that resembles daylight, find application in film projectors and as automobile headlamps. The noble gases are used in excimer lasers, which are based on short-lived electronically excited molecules known as excimers. The excimers used for lasers may be noble gas dimers such as Ar, Kr or Xe, or more commonly, the noble gas is combined with a halogen in"
"so, when pumping Nd:YAG with xenon, the continuum radiation must be used. All gases produce spectral lines which are specific to the gas, superimposed on a background of continuum radiation. With all gases, low current-densities produce mostly spectral lines, with the highest output being concentrated in the near-IR between 650 and 1000 nm. Krypton's strongest peaks are around 760 and 810 nm. Argon has many strong peaks at 670, 710, 760, 820, 860, and 920 nm. Neon has peaks around 650, 700, 850, and 880 nm. As current densities become higher, the output of continuum radiation will increase more than"
"in London. Neon was discovered when Ramsay chilled a sample of air until it became a liquid, then warmed the liquid and captured the gases as they boiled off. The gases nitrogen, oxygen, and argon had been identified, but the remaining gases were isolated in roughly their order of abundance, in a six-week period beginning at the end of May 1898. First to be identified was krypton. The next, after krypton had been removed, was a gas which gave a brilliant red light under spectroscopic discharge. This gas, identified in June, was named ""neon"", the Greek analogue of ""novum"" (new),"
"a particle collision in liquid xenon or argon. Cryogenic detector experiments include: CDMS, CRESST, EDELWEISS, EURECA. Noble liquid experiments include ZEPLIN, XENON, DEAP, ArDM, WARP, DarkSide, PandaX, and LUX, the Large Underground Xenon experiment. Both of these techniques focus strongly on their ability to distinguish background particles (which predominantly scatter off electrons) from dark matter particles (that scatter off nuclei). Other experiments include SIMPLE and PICASSO. Currently there has been no well-established claim of dark matter detection from a direct detection experiment, leading instead to strong upper limits on the mass and interaction cross section with nucleons of such dark"
"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"
"rays were evidently formed from spallation of oxygen, nitrogen, carbon and perhaps silicon in the cosmic ray sources or during their lengthy travel here. ""Cosmogenic"" isotopes of aluminium, beryllium, chlorine, iodine and neon, formed by spallation of terrestrial elements under cosmic ray bombardment, have been detected on Earth. Nuclear spallation is one of the processes by which a particle accelerator may be used to produce a beam of neutrons. A particle beam consisting of protons at around 1 GeV are shot into a target consisting of mercury, tantalum, lead or another heavy metal. The target nucleii are excited and upon"
"create the desired color (for example, ""neon"" type multi-colored advertising signs are often entirely krypton-based). Krypton produces much higher light power than neon in the red spectral line region, and for this reason, red lasers for high-power laser light-shows are often krypton lasers with mirrors that select the red spectral line for laser amplification and emission, rather than the more familiar helium-neon variety, which could not achieve the same multi-watt outputs. The krypton fluoride laser is important in nuclear fusion energy research in confinement experiments. The laser has high beam uniformity, short wavelength, and the spot size can be varied"
"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."
"are not known. Xenon dichloride, formed by the high-frequency irradiation of a mixture of xenon, fluorine, and silicon or carbon tetrachloride, is reported to be an endothermic, colorless, crystalline compound that decomposes into the elements at 80 °C. However, may be merely a van der Waals molecule of weakly bound Xe atoms and molecules and not a real compound. Theoretical calculations indicate that the linear molecule is less stable than the van der Waals complex. Three oxides of xenon are known: xenon trioxide () and xenon tetroxide (), both of which are dangerously explosive and powerful oxidizing agents, and xenon"
"spectral line. Krypton fluoride also makes a useful laser medium. From 1960 to 1983, the official length of a meter was defined by the 605 nm wavelength of the orange spectral line of krypton-86, because of the high power and relative ease of operation of krypton discharge tubes. Krypton was discovered in Britain in 1898 by Sir William Ramsay, a Scottish chemist, and Morris Travers, an English chemist, in residue left from evaporating nearly all components of liquid air. Neon was discovered by a similar procedure by the same workers just a few weeks later. William Ramsay was awarded the"
"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"
"the Greek word, , neuter singular form of (""neos""), meaning new. Neon is chemically inert, and no uncharged neon compounds are known. The compounds of neon currently known include ionic molecules, molecules held together by van der Waals forces and clathrates. During cosmic nucleogenesis of the elements, large amounts of neon are built up from the alpha-capture fusion process in stars. Although neon is a very common element in the universe and solar system (it is fifth in cosmic abundance after hydrogen, helium, oxygen and carbon), it is rare on Earth. It composes about 18.2 ppm of air by volume"
"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"
"bromine), and the middle transition metals (niobium, molybdenum, technetium, ruthenium, and possibly rhodium). This fraction includes the actinides most easily reusable as nuclear fuel in a thermal reactor, and the two long-lived fission products best suited to disposal by transmutation, Tc-99 and I-129, as well as Se-79. Noble gases (xenon, krypton) are volatile even without fluoridation, and will not condense except at much lower temperatures. Left behind are alkali metals (caesium, rubidium), alkaline earth metals (strontium, barium), lanthanides, the remaining actinides (americium, curium), remaining transition metals (yttrium, zirconium, palladium, silver) and post-transition metals (tin, indium, cadmium). This fraction contains the"
"can be absorbed before reaching the surface, impairing output efficiency. Due to its high-efficient, white output, xenon is used extensively for photographic applications, despite its great expense. In lasers, spectral-line emission is usually favored, as these lines tend to better match absorption lines of the lasing media. Krypton is also occasionally used, although it is even more expensive. At low current-densities, krypton's spectral-line output in the near-IR range is better matched to the absorption profile of neodymium-based laser media than xenon emission, and very closely matches the narrow absorption-profile of Nd:YAG. None of xenon's spectral lines match Nd:YAG's absorption lines"