ChemGlobe Periodic Table of the Elements
http://pol.spurious.biz/projects/chemglobe/ptoe/
/ ChemGlobe / Periodic Table of the Elements
 
 
Argon Non-
metal
Noblegas
Symbol: Ar
Atomic number: 18
Atomic mass: 39.948
Group: Noble Gas
CAS-number: 7440-37-1
 
Table Navigation Panel
Back to periodic table

Ne
Cl Ar Na
Kr

Go to element
Bottom

Physical data

Electronic data  Thermal data  Steric data
Shells: 2,8,8
Orbitals: [Ne] 3s2 3p6
Electronegativity: 3.2, --
1. Ionization potential: 15.7596 eV
2. Ionization potential: 27.629 eV
3. Ionization potential: 40.74 eV
Oxidation states: 0
Electrical conductivity: --
Melting point: -189.2 °C
Boiling point: -185.7 °C
Specific heat: 0.520 J/gK
Heat of fusion: 1.188 kJ/mol
Heat of vaporization: 6.447 kJ/mol
Thermal conductivity: 0.0001772 W/cmK
Atomic radius: 0.88 Å
Ionic radius: -- Å ()
Covalent radius: 0.98 Å
Atomic volume: 23.9 cm³/mol
Density (293 K): 0.0017824 g/cm³
Crystal structure: Cubic: Face centered
Legend     Pocket calculator
Top  Bottom

Isotopes

NuclideAbundance [%]MassSpinHalflifeDecay modeDecay tree
36Ar0.33734.96750--stable--
37Ar036.96673/235.0dECView
38Ar0.06337.96270--stable--
39Ar038.9647/2269yBeta-View
40Ar99.639.96240--stable--
41Ar0417/21.82hBeta-View
Legend
Top  Bottom

Other info

Name origin:Greek: argos (inactive)
Description:Colorless, odorless, tasteless noble gas. It is the third most abundant element in the earth's atmosphere and makes up about 1%.
Discovered by:Sir William Ramsey, Baron Rayleigh
Year:1894
Place:Scotland
Sources:Continuously released into the air by decay of radioactive potassium-40. Pure form is obtained from fractional distillation of liquid air.
Use(s):Used in lighting products. It is often used in filling incandescent light bulbs. Some is mixed with krypton in fluorescent lamps. Crystals in the semiconductor industry are grown in argon atmospheres.
Top
© 2000 ChemGlobe, Information Submit an error-report ChemGlobe