Scandium vs Promethium
| Property | Sc Scandium | Pm Promethium |
|---|---|---|
| Atomic number | 21 | 61 |
| Symbol | Sc | Pm |
| Name | Scandium | Promethium |
| Category | transition-metal | lanthanide |
| Standard Atomic Weight | 44.955908 u | 145 u |
| Period | 4 | 6 |
| Group | 3 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d1 | [Xe]6s24f5 |
| Oxidation states | [0, 1, 2, 3] | [2, 3] |
| Electronegativity (Pauling) | 1.36 | N/A |
| Electron affinity | 0.188 eV | 0.129 eV |
| Density | 2990 kg/m³ | 7260 kg/m³ |
| Melting point | 1540.85 °C | 1041.85 °C |
| Boiling point | 2835.85 °C | 2999.85 °C |
| Discovery year | 1879 | 1902 |