Neodymium vs Promethium
Pick up to 3 elements and see how they stack up.
| Property | Neodymium | Promethium |
|---|---|---|
| Atomic number | 60 | 61 |
| Atomic mass | 144.24 | 145 |
| Electronegativity | 1.14 | — |
| Melting point | 1,297 K (1,023.8 °C) | 1,315 K (1,041.8 °C) |
| Boiling point | 3,347 K (3,073.8 °C) | 3,273 K (2,999.8 °C) |
| Density | 7.01 g/cm³ | 7.26 g/cm³ |
| Atomic radius | 229 pm | 236 pm |
| Ionization energy | 5.525 eV | 5.55 eV |
| Discovered | 1885 | 1945 |
| Category | Lanthanide | Lanthanide |
| State at room temp. | Solid | Solid |
| Block | f | f |
| Group | — | — |
| Period | 6 | 6 |
| Valence electrons | 2 | 2 |
| Common charges | +3 | +3 |
| Electron configuration | [Xe] 4f4 6s2 | [Xe] 4f5 6s2 |