Calcium vs Hafnium
| Property | Ca Calcium | Hf Hafnium |
|---|---|---|
| Atomic number | 20 | 72 |
| Symbol | Ca | Hf |
| Name | Calcium | Hafnium |
| Category | alkaline-earth-metal | transition-metal |
| Standard Atomic Weight | 40.078 u | 178.49 u |
| Period | 4 | 6 |
| Group | 2 | 4 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s2 | [Xe]6s24f145d2 |
| Oxidation states | [1, 2] | [-2, 0, 1, 2, 3, 4] |
| Electronegativity (Pauling) | 1 | 1.3 |
| Electron affinity | 0.0245 eV | 0.178 eV |
| Density | 1540 kg/m³ | 1.330000e+4 kg/m³ |
| Melting point | 841.85 °C | 2232.85 °C |
| Boiling point | 1483.85 °C | 4602.85 °C |
| Discovery year | 1808 | 1911 |