Promethium vs Oganesson
| Property | Pm Promethium | Og Oganesson |
|---|---|---|
| Atomic number | 61 | 118 |
| Symbol | Pm | Og |
| Name | Promethium | Oganesson |
| Category | lanthanide | noble-gas |
| Standard Atomic Weight | 145 u | 294 u |
| Period | 6 | 7 |
| Group | N/A | 18 |
| Block | s | p |
| Phase at STP | solid | gas |
| Electron configuration | [Xe]6s24f5 | [Rn] 7s2 7p6 5f14 6d10(predicted) |
| Oxidation states | [2, 3] | [-1, 0, 1, 2, 4, 6] |
| Electronegativity (Pauling) | N/A | N/A |
| Electron affinity | 0.129 eV | 0.056 eV |
| Density | 7260 kg/m³ | 7000 kg/m³ |
| Melting point | 1041.85 °C | -273.15 °C |
| Boiling point | 2999.85 °C | -243.15 °C |
| Discovery year | 1902 | 2006 |