| Nb | Niobium | Transition Metal |
| Atomic number: | 41 | Atomic weight: | 92.90638 | ||
| Shells: | 2,8,18,12,1 | Orbitals: | [Kr] 4d4 5s1 | ||
| Melting point: | 2468°C ±10°C | Boiling point: | 4742°C | ||
| Covalent radius: | 1.34 | Å | Atomic volume: | 10.87 | cm³/mol |
| Atomic radius: | 2.08 | Å | Ionic radius: | .64 (+5) | Å |
| Electronegativity: | 1.6 | Oxidation states: | (5),3 | ||
| 1st ionization pot.: | 6.7589 | V | 2nd ionization pot.: | 14.32 | V |
| 3rd ionization pot.: | 25.04 | V | Specific heat: | 0.26 | J/gK |
| Heat of fusion: | 26.40 | kJ/mol | Heat of vapor.: | 682.0 | kJ/mol |
| Thermal conduct.: | 0.537 | W/cmK | Electrical conduct.: | 0.0693 | 10^6/cm ohm |
| Density: | 8.57 | g/cm³ | Valence: | 2,3,5 |