Radium vs Thorium
| Property | Ra Radium | Th Thorium |
|---|---|---|
| Atomic number | 88 | 90 |
| Symbol | Ra | Th |
| Name | Radium | Thorium |
| Category | alkaline-earth-metal | actinide |
| Standard Atomic Weight | 226 u | 232.0377 u |
| Period | 7 | 7 |
| Group | 2 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Rn]7s2 | [Rn]7s26d2 |
| Oxidation states | [2] | [-1, 1, 2, 3, 4] |
| Electronegativity (Pauling) | 0.9 | 1.3 |
| Electron affinity | 0.096 eV | 0.607 eV |
| Density | 5000 kg/m³ | 1.172000e+4 kg/m³ |
| Melting point | 699.85 °C | 1749.85 °C |
| Boiling point | 1139.85 °C | 4787.85 °C |
| Discovery year | 1898 | 1828 |