Promethium vs Copernicium
| Property | Pm Promethium | Cn Copernicium |
|---|---|---|
| Atomic number | 61 | 112 |
| Symbol | Pm | Cn |
| Name | Promethium | Copernicium |
| Category | lanthanide | transition-metal |
| Standard Atomic Weight | 145 u | 285 u |
| Period | 6 | 7 |
| Group | N/A | 12 |
| Block | s | s |
| Phase at STP | solid | gas |
| Electron configuration | [Xe]6s24f5 | [Rn] 7s2 5f14 6d10(predicted) |
| Oxidation states | [2, 3] | [2, 4] |
| Electronegativity (Pauling) | N/A | N/A |
| Electron affinity | 0.129 eV | -0.8 eV |
| Density | 7260 kg/m³ | 1.400000e+4 kg/m³ |
| Melting point | 1041.85 °C | -273.15 °C |
| Boiling point | 2999.85 °C | -165.15 °C |
| Discovery year | 1902 | 1996 |