41 Nb Niobium 92.906
Transition metal
Niobium 铌
[Kr] 4d⁴ 5s¹
- Period 5
- Group 5
- Block d
- Solid
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁴ 5s¹
Orbital diagram (valence)
- Electrons per shell
- 2, 8, 18, 12, 1
- Unpaired electrons
- 5
- Zeff (Slater)
- 2.80
Properties
- Atomic weight
- 92.906
- Electronegativity (Pauling)
- 1.6
- First ionization energy
- 652.1 kJ/mol
- Electron affinity
- 86.16 kJ/mol
- Covalent radius
- 164 pm
- van der Waals radius
- 207 pm
- Melting point
- 2750 K
- Boiling point
- 5017 K
- Density
- 8.57 g/cm³
- Melting / boiling point
- 2476.8 °C / 4743.9 °C
- Common oxidation states
- +5, +3
- Discovered
- 1801
Periodic trend
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).