Thallium vs Actinium
| Property | Tl Thallium | Ac Actinium |
|---|---|---|
| Atomic number | 81 | 89 |
| Symbol | Tl | Ac |
| Name | Thallium | Actinium |
| Category | post-transition-metal | actinide |
| Standard Atomic Weight | 204.3835 u | 227 u |
| Period | 6 | 7 |
| Group | 13 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f145d106p1 | [Rn]7s26d1 |
| Oxidation states | [-5, -2, -1, 1, 2, 3] | [3] |
| Electronegativity (Pauling) | 1.62 | 1.1 |
| Electron affinity | 0.377 eV | 0.35 eV |
| Density | 1.180000e+4 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | 303.85 °C | 1050.85 °C |
| Boiling point | 1472.85 °C | 3197.85 °C |
| Discovery year | 1861 | 1899 |