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

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
36Ar	0.337	34.9675	0	--	stable	--
37Ar	0	36.9667	3/2	35.0d	EC	View
38Ar	0.063	37.9627	0	--	stable	--
39Ar	0	38.964	7/2	269y	-	View
40Ar	99.6	39.9624	0	--	stable	--
41Ar	0	41	7/2	1.82h	-	View

Legend

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.