Atomic number 41
Name Niobium
Atomic mass 92.90638(2)
Electronic configuration [Kr] 4d4 5s1
Electronegativity 1.6
Atomic radius 137 pm
Ion radius 72 (+3) pm
Van der Waals radius pm
Ionization energy 652 kJ/mol
Electron affinity -86 kJ/mol
Oxidation states -1, 2, 3, 4, 5
Standard physical state solid
Bonding type metallic
Melting point 2750 °C
Boiling point 5017 °C
Density 8.57 g/cm³
Type transition metal
Year discovered 1801