Thorium vs Protactinium
Pick up to 3 elements and see how they stack up.
| Property | Thorium | Protactinium |
|---|---|---|
| Atomic number | 90 | 91 |
| Atomic mass | 232.04 | 231.04 |
| Electronegativity | 1.3 | 1.5 |
| Melting point | 2,023 K (1,749.8 °C) | 1,841 K (1,567.8 °C) |
| Boiling point | 5,061 K (4,787.8 °C) | 4,300 K (4,026.8 °C) |
| Density | 11.72 g/cm³ | 15.37 g/cm³ |
| Atomic radius | 237 pm | 243 pm |
| Ionization energy | 6.08 eV | 5.89 eV |
| Discovered | 1829 | 1913 |
| Category | Actinide | Actinide |
| State at room temp. | Solid | Solid |
| Block | f | f |
| Group | — | — |
| Period | 7 | 7 |
| Valence electrons | 2 | 2 |
| Common charges | +4 | +4, +5 |
| Electron configuration | [Rn] 6d2 7s2 | [Rn] 5f2 6d1 7s2 |