Comparison of Niobium and Molybdenum

Attribute	Molybdenum ×	Niobium ×
Atomic mass (u)	95.95	92.90637
Standard state	Solid	Solid
Oxidation states	+6	+3 +5
Electron configuration	[Kr]5s¹4d⁵	[Kr]5s¹4d⁴
Atomic radius (van der waals) (pm)	209	207
Electronegativity (pauling scale)	2.16	1.6
Electron affinity (eV)	0.746	0.893
Ionization energy (eV)	7.092	6.759
Boiling point (K)	4912	5017
Melting point (K)	2896	2750
Density (g/cm³)	10.2	8.57
Atomic number	42	41
Group name	Transition metal	Transition metal
Discovered (year)	1778	1801
Symbol	Mo	Nb