Promethium vs Mercury
| Property | Pm Promethium | Hg Mercury |
|---|---|---|
| Atomic number | 61 | 80 |
| Symbol | Pm | Hg |
| Name | Promethium | Mercury |
| Category | lanthanide | transition-metal |
| Standard Atomic Weight | 145 u | 200.592 u |
| Period | 6 | 6 |
| Group | N/A | 12 |
| Block | s | s |
| Phase at STP | solid | liquid |
| Electron configuration | [Xe]6s24f5 | [Xe]6s24f145d10 |
| Oxidation states | [2, 3] | [-2, 1, 2] |
| Electronegativity (Pauling) | N/A | 2 |
| Electron affinity | 0.129 eV | -0.5 eV |
| Density | 7260 kg/m³ | 1.353360e+4 kg/m³ |
| Melting point | 1041.85 °C | -38.83 °C |
| Boiling point | 2999.85 °C | 356.73 °C |
| Discovery year | 1902 | N/A |