Technetium vs Promethium
| Property | Tc Technetium | Pm Promethium |
|---|---|---|
| Atomic number | 43 | 61 |
| Symbol | Tc | Pm |
| Name | Technetium | Promethium |
| Category | transition-metal | lanthanide |
| Standard Atomic Weight | 98 u | 145 u |
| Period | 5 | 6 |
| Group | 7 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s24d5 | [Xe]6s24f5 |
| Oxidation states | [-3, -1, 1, 2, 3, 4, 5, 6, 7] | [2, 3] |
| Electronegativity (Pauling) | 1.9 | N/A |
| Electron affinity | 0.55 eV | 0.129 eV |
| Density | 1.100000e+4 kg/m³ | 7260 kg/m³ |
| Melting point | 2156.85 °C | 1041.85 °C |
| Boiling point | 4264.85 °C | 2999.85 °C |
| Discovery year | 1937 | 1902 |