Comparison of Chlorine and Radon

Attribute	Chlorine ×	Radon ×
Atomic mass (u)	35.45	222.01758
Standard state	Gas	Gas
Oxidation states	-1 +1 +5 +7	0
Electron configuration	[Ne]3s²3p⁵	[Xe]6s²4f¹⁴5d¹⁰6p⁶
Atomic radius (van der waals) (pm)	175	220
Electronegativity (pauling scale)	3.16	-
Electron affinity (eV)	3.617	-
Ionization energy (eV)	12.968	10.745
Boiling point (K)	239.11	211.45
Melting point (K)	171.65	202
^1↑Density (g/cm³)	0.003214	0.00973
Atomic number	17	86
Group name	Halogen	Noble gas
Symbol	Cl	Rn
Discovered (year)	1774	1900