Comparison of Helium and Oxygen

Attribute	Oxygen ×	Helium ×
Electron affinity (eV)	1.461	-
Electronegativity (pauling scale)	3.44	-
Atomic mass (u)	15.999	4.0026
Standard state	Gas	Gas
Oxidation states	-2	0
Electron configuration	[He]2s²2p⁴	1s²
Ionization energy (eV)	13.618	24.587
Atomic radius (van der waals) (pm)	152	140
Boiling point (K)	90.2	4.22
Melting point (K)	54.36	0.95
Density (g/cm³)	0.001429	0.0001785
Atomic number	8	2
Group name	Nonmetal	Noble gas
Discovered (year)	1774	1868
Symbol	O	He