Promethium vs Samarium
Pick up to 3 elements and see how they stack up.
| Property | Promethium | Samarium |
|---|---|---|
| Atomic number | 61 | 62 |
| Atomic mass | 145 | 150.36 |
| Electronegativity | — | 1.17 |
| Melting point | 1,315 K (1,041.8 °C) | 1,345 K (1,071.8 °C) |
| Boiling point | 3,273 K (2,999.8 °C) | 2,067 K (1,793.8 °C) |
| Density | 7.26 g/cm³ | 7.52 g/cm³ |
| Atomic radius | 236 pm | 229 pm |
| Ionization energy | 5.55 eV | 5.644 eV |
| Discovered | 1945 | 1879 |
| Category | Lanthanide | Lanthanide |
| State at room temp. | Solid | Solid |
| Block | f | f |
| Group | — | — |
| Period | 6 | 6 |
| Valence electrons | 2 | 2 |
| Common charges | +3 | +2, +3 |
| Electron configuration | [Xe] 4f5 6s2 | [Xe] 4f6 6s2 |