Xenon
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| General
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| Name, Symbol, Number
| xenon, Xe, 54
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| Chemical series
| Noble gases
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| Group, Period, Block
| 18 (VIIIA), 5, p
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| Density, Hardness
| 5.9 kg/m3(273 K), NA
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| Appearance
| colorless
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| Atomic properties
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| Atomic weight
| 131.293 amu
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| Atomic radius (calc.)
| no data (108) pm
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| Covalent radius
| 130 pm
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| van der Waals radius
| 216 pm
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| Electron configuration
| [Kr]4d10 5s2 5p6
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| e- 's per energy level
| 2, 8, 18, 18, 8
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| Oxidation states (Oxide)
| 0 (weak acid)
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| Crystal structure
| cubic face centered
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| Physical properties
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| State of matter
| gas (nonmagnetic)
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| Melting point
| 161.4 K (-169.1 °F)
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| Boiling point
| 165.1 K (-162 °F)
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| Molar volume
| 35.92 ×10-6 m3/mol
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| Heat of vaporization
| 12.636 kJ/mol
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| Heat of fusion
| 2.297 kJ/mol
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| Vapor pressure
| NA
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| Speed of sound
| 1090 m/s at 293.15 K
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| Miscellaneous
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| Electronegativity
| 2.6 (Pauling scale)
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| Specific heat capacity
| 158 J/(kg*K)
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| Electrical conductivity
| no data
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| Thermal conductivity
| 0.00569 W/(m*K)
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| 1st ionization potential
| 1170.4 kJ/mol
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| 2nd ionization potential
| 2046.4 kJ/mol
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| 3rd ionization potential
| 3099.4 kJ/mol
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| Most stable isotopes
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| iso
| NA
| half-life
| DM
| DE
| DP
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| 124Xe
| 0.1%
| Xe is stable with 70 neutrons
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| 126Xe
| 0.09%
| Xe is stable with 72 neutrons
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| 128Xe
| 1.91%
| Xe is stable with 74 neutrons
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| 129Xe
| 26.4%
| Xe is stable with 75 neutrons
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| 130Xe
| 4.1%
| Xe is stable with 76 neutrons
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| 131Xe
| 21.29%
| Xe is stable with 77 neutrons
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| 132Xe
| 26.9%
| Xe is stable with 78 neutrons
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| 134Xe
| 10.4%
| Xe is stable with 80 neutrons
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| 136Xe
| 8.9%
| 2.36 E21 y
| Beta-
| no data
| 136Ba
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| SI units & STP are used except where noted.
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Xenon is a chemical element in the periodic table that has the symbol Xe and atomic number 54. A colorless, very heavy, odorless noble gas, xenon occurs in the earth's atmosphere in trace amounts and was part of the first noble gas compound synthesized.
Notable characteristics
Xenon is a member of the zero-valence elements that are called noble or inert gases. The word "inert" is no longer used to describe this chemical series since some zero valence elements do form compounds. In a gas filled tube, xenon emits a blue glow when the gas is excited by electrical discharge. Using several hundred kilobars of pressure, metallic xenon has been made. Xenon can also form clathrates with water when atoms of it are trapped in a lattice of the water molecules.
Applications
This gas is most widely and most famously used in light-emitting devices called Xenon flash lamps, which are used in photographic flashes, stroboscopic lamps, to excite the active medium in lasers which then generate coherent light, in bactericidal lamps (rarely), and in certain dermatological uses. Other uses;
History
Xenon (Greek xenon meaning "stranger") was discovered by William Ramsay and Morris Travers in 1898 in the residue left over from evaporating components of liquid air.
Occurrence
It is a trace gas in Earth's atmosphere, occurring in one part in twenty million. The element is obtained commercially through extraction from the residues of liquefied air. This noble gas is naturally found in gases emitted from some mineral springs. Xe-133 and Xe-135 are synthesized by neutron irradiation within air-cooled nuclear reactors.
Compounds
Before 1962, xenon and the other noble gases were generally considered to be chemically inert and not able to form compounds. Evidence since this time has been mounting that xenon, along with other noble gases, do in fact form compounds. Some of the xenon compounds are; difluoride, hexafluoride, sodium perxenate, tetrafluoride, xenon deuterate, xenon hydrate. The highly explosive compound xenon trioxide has also been made. There are at least 80 xenon compounds in which fluorine or oxygen are bonded to xenon. Some compounds of xenon are colored but most are colorless.
Isotopes
Naturally occurring xenon is made of eight stable and one slightly radioactive isotopes. Beyond these stable forms, there are 20 unstable isotopes that have been studied. Xe-129 is produced by beta decay of I-129 (half-life: 16 million years); Xe-131m, Xe-133, Xe-133m, and Xe-135 are fission products of both U-235 and Pu-239, and therefore used as indicators of nuclear explosions. Radioactive xenon isotopes are also found emanating from nuclear reactors.
Because Xe is a tracer for two parent isotopes, Xe isotope ratios in meteorites are a powerful tool for studying the formation of the solar system. The I-Xe method of dating gives the time elapsed between nucleosynthesis and the condensation of a solid object from the solar nebula. Xenon isotopes are also a powerful tool for understanding terrestrial differentiation. Excess Xe-129 found in carbon dioxide well gases from New Mexico was believed to be from the decay of mantle-derived gases soon after Earth's formation.
Precautions
The gas can be safely kept in normal sealed glass containers at standard temperature and pressure. Xenon is non-toxic, but many of its compounds are highly toxic due to their strong oxidation properties.
References
