Comparison of Zinc and Selenium

Attribute	Selenium ×	Zinc ×
Standard state	Solid	Solid
Electron affinity (eV)	2.021	-
Electron configuration	[Ar]4s²3d¹⁰4p⁴	[Ar]4s²3d¹⁰
Atomic mass (u)	78.97	65.4
Electronegativity (pauling scale)	2.55	1.65
Oxidation states	-2 +4 +6	+2
Ionization energy (eV)	9.752	9.394
Atomic radius (van der waals) (pm)	190	139
Boiling point (K)	958	1180
Melting point (K)	493.65	692.68
Density (g/cm³)	4.809	7.134
Atomic number	34	30
Group name	Nonmetal	Transition metal
Discovered (year)	1817	1746
Symbol	Se	Zn