Niobium |
| Symbol | Nb |
|---|---|
| Latin name | Niobium |
| Atomic number | 41 |
| Period | 5 |
| Element category | Transition elements |
| Relative atomic mass | 92.90638 |
| Group | V.B |
| Electronegativity | 1.6 |
| Oxidation numbers | 3, 5 |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d4 5s1 |
| Density [g/cm3] | 8.57 |
| State | Solid |
| Melting point [°C] | 2468 |
| Boiling point [°C] | 4742 |
| Atomic radius [pm] | 198 |
| Covalent radius [pm] | 137 |
| Thermal conductivity [W m-1K-1] | 53.7 |
| Heat capacity [J K-1g-1] | 0.265 |
| Discovery | 1801 |
| Hardness [Mohs scale] | 6.0 |
| Vickers hardness [MPa] | 1320 |
| Brinell hardness [MPa] | 736 |
| Young's modulus [GPa] | 105 |
| Electrical conductivity [S m-1] | 6.7 · 106 |
| Shear modulus [GPa] | 38 |
| 1.st ionization energy [eV] | 6.7589 |
| 2.nd ionization energy [eV] | 14.32 |
| 3.rd ionization energy [eV] | 25.04 |
| Stable isotopes | 1 |
| Unstable isotopes | 21 |