Polonium vs Actinium
| Property | Po Polonium | Ac Actinium |
|---|---|---|
| Atomic number | 84 | 89 |
| Symbol | Po | Ac |
| Name | Polonium | Actinium |
| Category | metalloid | actinide |
| Standard Atomic Weight | 209 u | 227 u |
| Period | 6 | 7 |
| Group | 16 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d106p4 | [Rn]7s26d1 |
| Oxidation states | [-2, 2, 4, 5, 6] | [3] |
| Electronegativity (Pauling) | 2 | 1.1 |
| Electron affinity | 1.9 eV | 0.35 eV |
| Density | 9320 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | 253.85 °C | 1050.85 °C |
| Boiling point | 961.85 °C | 3197.85 °C |
| Discovery year | 1898 | 1899 |