Strontium vs Actinium
| Property | Sr Strontium | Ac Actinium |
|---|---|---|
| Atomic number | 38 | 89 |
| Symbol | Sr | Ac |
| Name | Strontium | Actinium |
| Category | alkaline-earth-metal | actinide |
| Standard Atomic Weight | 87.62 u | 227 u |
| Period | 5 | 7 |
| Group | 2 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s2 | [Rn]7s26d1 |
| Oxidation states | [1, 2] | [3] |
| Electronegativity (Pauling) | 0.95 | 1.1 |
| Electron affinity | 0.052 eV | 0.35 eV |
| Density | 2640 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | 776.85 °C | 1050.85 °C |
| Boiling point | 1381.85 °C | 3197.85 °C |
| Discovery year | 1792 | 1899 |