Comparison of Chlorine and Krypton

Attribute	Krypton ×	Chlorine ×
Atomic mass (u)	83.8	35.45
Standard state	Gas	Gas
Oxidation states	0	-1 +1 +5 +7
Electron configuration	[Ar]4s²3d¹⁰4p⁶	[Ne]3s²3p⁵
Atomic radius (van der waals) (pm)	202	175
Electronegativity (pauling scale)	3	3.16
Electron affinity (eV)	-	3.617
Ionization energy (eV)	14	12.968
Boiling point (K)	119.93	239.11
Melting point (K)	115.79	171.65
Density (g/cm³)	0.003733	0.003214
Atomic number	36	17
Group name	Noble gas	Halogen
Symbol	Kr	Cl
Discovered (year)	1898	1774