Boron vs Promethium
| Property | B Boron | Pm Promethium |
|---|---|---|
| Atomic number | 5 | 61 |
| Symbol | B | Pm |
| Name | Boron | Promethium |
| Category | metalloid | lanthanide |
| Standard Atomic Weight | 10.8135 u | 145 u |
| Period | 2 | 6 |
| Group | 13 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [He]2s22p1 | [Xe]6s24f5 |
| Oxidation states | [-5, -1, 0, 1, 2, 3] | [2, 3] |
| Electronegativity (Pauling) | 2.04 | N/A |
| Electron affinity | 0.27972 eV | 0.129 eV |
| Density | 2370 kg/m³ | 7260 kg/m³ |
| Melting point | 2074.85 °C | 1041.85 °C |
| Boiling point | 3999.85 °C | 2999.85 °C |
| Discovery year | 1808 | 1902 |