The Noble gases are Helium, Neon, Krypton, Xenon, Radon and which other element?
"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"
"suggesting a solar-neon reservoir in the Earth. Neon is the second-lightest noble gas, after helium. It glows reddish-orange in a vacuum discharge tube. Also, neon has the narrowest liquid range of any element: from 24.55 K to 27.05 K (−248.45 °C to −245.95 °C, or −415.21 °F to −410.71 °F). It has over 40 times the refrigerating capacity (per unit volume) of liquid helium and three times that of liquid hydrogen. In most applications it is a less expensive refrigerant than helium. Neon plasma has the most intense light discharge at normal voltages and currents of all the noble gases."
"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"
"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"
"or neon are known. The noble gases—including helium—can form stable molecular ions in the gas phase. The simplest is the helium hydride molecular ion, HeH, discovered in 1925. Because it is composed of the two most abundant elements in the universe, hydrogen and helium, it is believed to occur naturally in the interstellar medium, although it has not been detected yet. In addition to these ions, there are many known neutral excimers of the noble gases. These are compounds such as ArF and KrF that are stable only when in an excited electronic state; some of them find application in"
"column of the periodic table, also known as group 0 or group 18. Noble gases are also called as aerogens but this nomenclature of the group is not officially accepted by the IUPAC. All of the noble gases have full outer shells with eight electrons. However, at the top of the noble gases is helium, with a shell that is full with only two electrons. The fact that their outer shells are full means they rarely react with other elements, which led to their original title of ""inert"". Because of their chemical properties, these gases are also used in the"
"of Ar, Kr, and Xe. (For instance, radioactive isotopes of krypton and xenon are difficult to store and dispose, and compounds of these elements may be more easily handled than the gaseous forms.) In addition, clathrates of radioisotopes may provide suitable formulations for experiments requiring sources of particular types of radiation; hence. Kr clathrate provides a safe source of beta particles, while Xe clathrate provides a useful source of gamma rays. 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"
"applied at a temperature of to convert it to a solid. The noble gases up to xenon have multiple stable isotopes. Radon has no stable isotopes; its longest-lived isotope, Rn, has a half-life of 3.8 days and decays to form helium and polonium, which ultimately decays to lead. Melting and boiling points generally increase going down the group. The noble gas atoms, like atoms in most groups, increase steadily in atomic radius from one period to the next due to the increasing number of electrons. The size of the atom is related to several properties. For example, the ionization potential"
"inert. It is one of the so-called ""noble gases"". Neon is a trace component of the atmosphere without any biological role. Period 2 element A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behavior of the elements as their atomic number increases; a new row is started when chemical behavior begins to repeat, creating columns of elements with similar properties. The second period contains the elements lithium, beryllium, boron,"
"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"
"since all isotopes are radiogenic nuclides from radioactive decay. (It is not known if any synthetic elements with atomic number above 108 are gases.) The elements which are stable two atom homonuclear molecules at standard temperature and pressure (STP), are hydrogen (H), nitrogen (N) and oxygen (O), plus the halogens fluorine (F) and chlorine (Cl). The noble gases are all monatomic. In the industrial gases industry the term ""elemental gases"" (or sometimes less accurately ""molecular gases"") is used to distinguish these gases from molecules that are also chemical compounds. These elements are all nonmetals. Radon is chemically stable, but it"
"an example, the adjacent table lists the 2004 prices in the United States for laboratory quantities of each gas. Noble gases have very low boiling and melting points, which makes them useful as cryogenic refrigerants. In particular, liquid helium, which boils at , is used for superconducting magnets, such as those needed in nuclear magnetic resonance imaging and nuclear magnetic resonance. Liquid neon, although it does not reach temperatures as low as liquid helium, also finds use in cryogenics because it has over 40 times more refrigerating capacity than liquid helium and over three times more than liquid hydrogen. Helium"
"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"
"century, their inertness was ascribed to a full valence shell of electrons which render them very chemically stable and nonreactive. All noble gases have full ""s"" and ""p"" outer electron shells (except helium, which has no ""p"" sublevel), and so do not form chemical compounds easily. Their high ionization energy and almost zero electron affinity explain their non-reactivity. In 1933, Linus Pauling predicted that the heavier noble gases would be able to form compounds with fluorine and oxygen. Specifically, he predicted the existence of krypton hexafluoride (KrF) and xenon hexafluoride (XeF), speculated that XeF might exist as an unstable compound,"
"with atomic masses larger than many normally solid elements. Chemically, the noble gases have relatively high ionization energies, negative electron affinities, and relatively high electronegativities. Compounds of the noble gases number less than half a thousand, with most of these occurring via oxygen or fluorine combining with either krypton, xenon or radon. The status of the period 7 congener of the noble gases, oganesson (Og), is not known—it may or may not be a noble gas. It was originally predicted to be a noble gas but may instead be a fairly reactive solid with an anomalously low first ionisation potential,"
"outside of the context of electron configurations: When the noble gases (then called ""inert gases"") were first discovered around 1900, they were known as ""group 0"", reflecting no chemical reactivity of these elements known at that point, and helium was placed on the top of that group, as it did share the extreme chemical inertness seen throughout the group. As the group changed its formal number, many authors continued to assign helium directly above neon, in group 18; one of the examples of such placing is the current IUPAC table. Hydrogen's chemical properties are not very close to those of"
"lithium and fluorine (appearing twice), or left floating above the other elements and not assigned to any group in the periodic table. Helium is almost always placed above neon (which is in the p-block) in the periodic table as a noble gas, although it is occasionally placed above beryllium due to their similar electron configuration. 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 H. With an atomic mass of 1.00794 amu, hydrogen is the lightest element. Hydrogen is"
"of Hale–Bopp revealed the presence of many organic chemicals, several of which had never been detected in comets before. These complex molecules may exist within the cometary nucleus, or might be synthesised by reactions in the comet. Hale–Bopp was the first comet where the noble gas argon was detected. Noble gases are chemically inert and highly volatile, and since different noble elements have different sublimation temperatures, they can be used for probing the temperature histories of the cometary ices. Krypton has a sublimation temperature of 16–20 K and was found to be depleted more than 25 times relative to the"
"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"
"put in a gas cylinder (except perhaps if it is used as a fuel) Propane would be considered an industrial gas when used as a refrigerant, but not when used as a refrigerant in LNG production, even though this is an overlapping technology. The known chemical elements which are, or can be obtained from natural resources and which are gaseous are hydrogen, nitrogen, oxygen, fluorine, chlorine, plus the noble gases; and are collectively referred to by chemists as the ""elemental gases"". These elements are all primordial apart from the noble gas radon which is a trace radioisotope which occurs naturally"
"Ni−C−O by 36 cm. NeAuF and NeBeS have been isolated in noble gas matrixes. NeBeCO has been detected by infrared spectroscopy in a solid neon matrix. It was made from beryllium gas, dioxygen and carbon monoxide. The cyclic molecule BeO can be made by evaporating Be with a laser with oxygen and an excess of inert gas. It coordinates two noble gas atoms and has had spectra measured in solid neon matrices. Known neon containing molecules are the homoleptic Ne.BeO.Ne, and heteroleptic Ne.BeO.Ar and Ne.BeO.Kr. The Neon atoms are attracted to the beryllium atoms as they have a positive charge"
"Radon Radon is a chemical element with 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. Its most stable isotope, Rn, has a half-life of only 3.8 days, making radon one of the rarest elements since it decays away so quickly. However, since thorium and uranium are two of the most common radioactive elements"
"Argon Argon is a chemical element with symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in the Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust. Nearly all of the argon in"
"noble gases have negative electron affinities) and high electronegativity values noting that, in general, the higher an element's ionisation energy, electron affinity, and electronegativity, the more nonmetallic that element is. Nonmetals (including – to a limited extent – xenon and probably radon) usually exist as anions or oxyanions in aqueous solution; they generally form ionic or covalent compounds when combined with metals (unlike metals, which mostly form alloys with other metals); and have acidic oxides whereas the common oxides of nearly all metals are basic. Complicating the chemistry of the nonmetals is the first row anomaly seen particularly in hydrogen,"
"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"
"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"
"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"
"elements include boron, cobalt, hafnium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Alloys or compounds may also be used, such as high-boron steel, silver-indium-cadmium alloy, boron carbide, zirconium diboride, titanium diboride, hafnium diboride, gadolinium nitrate, gadolinium titanate, dysprosium titanate and boron carbide - europium hexaboride composite. The material choice is influenced by the neutron energy in the reactor, their resistance to neutron-induced swelling and the required mechanical and lifespan properties. The rods may have the form of tubes filled with neutron-absorbing pellets or powder. They can be made out of stainless steel or other neutron window"
"makes it more potent than the usual nitrous oxide, and because it is readily eliminated from the body, resulting in faster recovery. Xenon finds application in medical imaging of the lungs through hyperpolarized MRI. Radon, which is highly radioactive and is only available in minute amounts, is used in radiotherapy. Noble gases, particularly xenon, are predominantly used in ion engines due to their inertness. Since ion engines are not driven by chemical reactions, chemically inert fuels are desired to prevent unwanted reaction between the fuel and anything else on the engine. The color of gas discharge emission depends on several"
"that are called noble gases. It is inert to most common chemical reactions, such as combustion, because the outer valence shell contains eight electrons. This produces a stable, minimum energy configuration in which the outer electrons are tightly bound. 1037 kJ/mol is required to extract one electron from its shells (also known as the first ionization energy). In accordance with periodic trends, radon has a lower electronegativity than the element one period before it, xenon, and is therefore more reactive. Early studies concluded that the stability of radon hydrate should be of the same order as that of the hydrates"
"molecule that led Bartlett to attempt oxidizing xenon using platinum hexafluoride, an oxidizing agent known to be strong enough to react with oxygen. Noble gases cannot accept an electron to form stable anions; that is, they have a negative electron affinity. The macroscopic physical properties of the noble gases are dominated by the weak van der Waals forces between the atoms. The attractive force increases with the size of the atom as a result of the increase in polarizability and the decrease in ionization potential. This results in systematic group trends: as one goes down group 18, the atomic radius,"
"radioactive noble gas with a half-life of 10.76 years. It is produced by the fission of uranium and plutonium, such as in nuclear bomb testing and nuclear reactors. Kr is released during the reprocessing of fuel rods from nuclear reactors. Concentrations at the North Pole are 30% higher than at the South Pole due to convective mixing. Like the other noble gases, krypton is highly chemically unreactive. The rather restricted chemistry of krypton in its only known nonzero oxidation state of +2 parallels that of the neighboring element bromine in the +1 oxidation state; due to the scandide contraction it"
"as nonmetals. Among the reactive nonmetals, carbon, phosphorus, selenium, and iodine—which border the metalloids—show some metallic character, as does hydrogen. Among the noble gases, radon is the most metallic and begins to show some cationic behaviour, which is unusual for a nonmetal. The seven metalloids are boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), and astatine (At). On a standard periodic table, they occupy a diagonal area in the p-block extending from boron at the upper left to astatine at lower right, along the dividing line between metals and nonmetals shown on some periodic tables. They"