Comparison of Argon and Krypton

Attribute	Krypton ×	Argon ×
Electronegativity (pauling scale)	3	-
Atomic mass (u)	83.8	39.9
Standard state	Gas	Gas
Oxidation states	0	0
Electron configuration	[Ar]4s²3d¹⁰4p⁶	[Ne]3s²3p⁶
Ionization energy (eV)	14	15.76
Atomic radius (van der waals) (pm)	202	188
Boiling point (K)	119.93	87.3
Melting point (K)	115.79	83.8
Density (g/cm³)	0.003733	0.0017837
Atomic number	36	18
Group name	Noble gas	Noble gas
Discovered (year)	1898	1894
Symbol	Kr	Ar