Radium vs Actinium
Pick up to 3 elements and see how they stack up.
| Property | Radium | Actinium |
|---|---|---|
| Atomic number | 88 | 89 |
| Atomic mass | 226 | 227 |
| Electronegativity | 0.9 | 1.1 |
| Melting point | 973 K (699.8 °C) | 1,323 K (1,049.8 °C) |
| Boiling point | 2,010 K (1,736.8 °C) | 3,471 K (3,197.8 °C) |
| Density | 5.5 g/cm³ | 10.07 g/cm³ |
| Atomic radius | 283 pm | 260 pm |
| Ionization energy | 5.279 eV | 5.17 eV |
| Discovered | 1898 | 1899 |
| Category | Alkaline earth metal | Actinide |
| State at room temp. | Solid | Solid |
| Block | s | f |
| Group | 2 | — |
| Period | 7 | 7 |
| Valence electrons | 2 | 2 |
| Common charges | +2 | +3 |
| Electron configuration | [Rn] 7s2 | [Rn] 6d1 7s2 |