Symbol Ar Atomic radius: pm - Fusion: kJ/Mole 1.18
Name Argon Ionic radius: pm - Boiling point: C -186
Atomic number 18 Electron affinity Unstable anion Melting point: C -189
Atomic weight 39.95 1st  ion potential 15.76 Specific Heat Cap: J/(g K) 0.52
Classification Noble gas Natural form Gas Thermal Cond: W/(cm K) <0.001
Configuration [Ne]3s2p6 Crystal structure FCC Electrical Cond -
Oxidation states - Density 1.78 Abundance: mg/kg-crust 3.5
Electronegativity - Vaporization: kJ/Mole 6.43    
Argon gas was isolated in 1894 by the English scientists Lord Rayleigh (John William Strutt) and Sir William Ramsey. Uses - lasers, light bulbs