Hafnium |
| Symbol | Hf |
|---|---|
| Latin name | Hafnium |
| Atomic number | 72 |
| Period | 6 |
| Element category | Transition elements |
| Relative atomic mass | 178.49 |
| Group | IV.B |
| Electronegativity | 1.3 |
| Oxidation numbers | 4 |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d2 6s2 |
| Density [g/cm3] | 13.3 |
| State | Solid |
| Melting point [°C] | 2227 |
| Boiling point [°C] | 4600 |
| Atomic radius [pm] | 208 |
| Covalent radius [pm] | 150 |
| Thermal conductivity [W m-1K-1] | 23 |
| Heat capacity [J K-1g-1] | 0.14 |
| Discovery | 1864 |
| Hardness [Mohs scale] | 5.5 |
| Vickers hardness [MPa] | 1760 |
| Brinell hardness [MPa] | 1700 |
| Young's modulus [GPa] | 78 |
| Electrical conductivity [S m-1] | 3.3 · 106 |
| Shear modulus [GPa] | 30 |
| 1.st ionization energy [eV] | 6.8251 |
| 2.nd ionization energy [eV] | 14.925 |
| 3.rd ionization energy [eV] | 23.32 |
| Stable isotopes | 6 |
| Unstable isotopes | 15 |