Zirconium vs Thorium
| Property | Zr Zirconium | Th Thorium |
|---|---|---|
| Atomic number | 40 | 90 |
| Symbol | Zr | Th |
| Name | Zirconium | Thorium |
| Category | transition-metal | actinide |
| Standard Atomic Weight | 91.224 u | 232.0377 u |
| Period | 5 | 7 |
| Group | 4 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s24d2 | [Rn]7s26d2 |
| Oxidation states | [1, 2, 3, 4] | [-1, 1, 2, 3, 4] |
| Electronegativity (Pauling) | 1.33 | 1.3 |
| Electron affinity | 0.426 eV | 0.607 eV |
| Density | 6520 kg/m³ | 1.172000e+4 kg/m³ |
| Melting point | 1854.85 °C | 1749.85 °C |
| Boiling point | 4408.85 °C | 4787.85 °C |
| Discovery year | 1789 | 1828 |