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72
Hf
178.49
Hafnium
Transition metals · Group 4 · Period 6
Atomic properties
| Atomic number | 72 |
|---|---|
| Symbol | Hf |
| Standard atomic weight | 178.49 |
| Classification | Transition metals |
| Group | 4 |
| Period | 6 |
| Block | d-block |
| Electron configuration | [Xe] 4f14 5d2 6s2 |
| Electronegativity (Pauling) | 1.30 |
| Common oxidation states | +4 |
Physical properties
| Phase at 20 °C | Solid |
|---|---|
| Density | 13.31 g/cm³ |
| Melting point | 2233 °C |
| Boiling point | 4603 °C |
| Discovered | 1923 |
| CAS number | — |