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Argon, 00Ar
Vial containing a violet glowing gas
Argon
Pronunciation /ˈɑːrɡɒn/ ( AR-gon)
Appearancecolorless gas exhibiting a lilac/violet glow when placed in an electric field
Standard atomic weight Ar°(Ar)
Argon in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson
Ne

Ar

Kr
chlorineargonpotassium
Group group 18 (noble gases)
Period period 3
Block  p-block
Electron configuration[ Ne] 3s2 3p6
Electrons per shell2, 8, 8
Physical properties
Phase at  STPgas
Melting point83.81  K ​(−189.34 °C, ​−308.81 °F)
Boiling point87.302 K ​(−185.848 °C, ​−302.526 °F)
Density (at STP)1.784 g/L
when liquid (at  b.p.)1.3954 g/cm3
Triple point83.8058 K, ​68.89 kPa [3]
Critical point150.687 K, 4.863 MPa [3]
Heat of fusion1.18  kJ/mol
Heat of vaporization6.53 kJ/mol
Molar heat capacity20.85 [4] J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at  T (K)   47 53 61 71 87
Atomic properties
Oxidation states0
ElectronegativityPauling scale: no data
Ionization energies
  • 1st: 1520.6 kJ/mol
  • 2nd: 2665.8 kJ/mol
  • 3rd: 3931 kJ/mol
  • ( more)
Covalent radius106±10  pm
Van der Waals radius188 pm
Color lines in a spectral range
Spectral lines of argon
Other properties
Natural occurrence primordial
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for argon
Speed of sound323 m/s (gas, at 27 °C)
Thermal conductivity17.72×10−3  W/(m⋅K)
Magnetic ordering diamagnetic [5]
CAS Number7440-37-1
History
Discovery and first isolation Lord Rayleigh and William Ramsay (1894)
Isotopes of argon
Main isotopes [6] Decay
abun­dance half-life (t1/2) mode pro­duct
36Ar 0.334% stable
37Ar trace 35 d ε 37Cl
38Ar 0.0630% stable
39Ar trace 268 y β 39K
40Ar 99.6% stable
41Ar trace 109.34 min β 41K
42Ar synth 32.9 y β 42K
  Category: Argon
| references

References

  1. ^ "Standard Atomic Weights: Argon". CIAAW. 2017.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi: 10.1515/pac-2019-0603. ISSN  1365-3075.
  3. ^ a b Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.121. ISBN  1-4398-5511-0.
  4. ^ Shuen-Chen Hwang, Robert D. Lein, Daniel A. Morgan (2005). "Noble Gases". Kirk Othmer Encyclopedia of Chemical Technology. Wiley. pp. 343–383. doi:10.1002/0471238961.0701190508230114.a01.
  5. ^ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN  0-8493-0486-5.
  6. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi: 10.1088/1674-1137/abddae.
  7. ^ hello spectral world-old
  8. ^ hello spectral world-new
  9. ^ Standard Atomic Weights 2013. Commission on Isotopic Abundances and Atomic Weights