72Hf178.49
Hafnium (Hf)
Element 72 · Transition metal
Hafnium (Hf) is a chemical element with atomic number 72. It is classified as a transition metal in period 6, group 4 of the periodic table (the d-block). Its standard atomic weight is 178.49 u and its ground-state electron configuration is [Xe] 4f¹⁴ 5d² 6s².
Hafnium facts
| Atomic number (Z) | 72 |
|---|---|
| Symbol | Hf |
| Standard atomic weight | 178.49 u |
| Category | Transition metal |
| Group | 4 |
| Period | 6 |
| Block | d-block |
| Electron configuration | [Xe] 4f¹⁴ 5d² 6s² |
| Electronegativity (Pauling) | 1.3 |
| State at 20 °C | Solid |
| Protons / electrons | 72 / 72 |
| Neutrons (most common isotope, approx.) | 106 |
| Molar mass | 178.49 g/mol |