Zirconium vs Hafnium
| Property | Zr Zirconium | Hf Hafnium |
|---|---|---|
| Atomic number | 40 | 72 |
| Symbol | Zr | Hf |
| Name | Zirconium | Hafnium |
| Category | transition-metal | transition-metal |
| Standard Atomic Weight | 91.224 u | 178.49 u |
| Period | 5 | 6 |
| Group | 4 | 4 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s24d2 | [Xe]6s24f145d2 |
| Oxidation states | [1, 2, 3, 4] | [-2, 0, 1, 2, 3, 4] |
| Electronegativity (Pauling) | 1.33 | 1.3 |
| Electron affinity | 0.426 eV | 0.178 eV |
| Density | 6520 kg/m³ | 1.330000e+4 kg/m³ |
| Melting point | 1854.85 °C | 2232.85 °C |
| Boiling point | 4408.85 °C | 4602.85 °C |
| Discovery year | 1789 | 1911 |