Calcium vs Astatine
| Property | Ca Calcium | At Astatine |
|---|---|---|
| Atomic number | 20 | 85 |
| Symbol | Ca | At |
| Name | Calcium | Astatine |
| Category | alkaline-earth-metal | halogen |
| Standard Atomic Weight | 40.078 u | 210 u |
| Period | 4 | 6 |
| Group | 2 | 17 |
| Block | s | p |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s2 | [Xe]6s24f145d106p5 |
| Oxidation states | [1, 2] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 1 | 2.2 |
| Electron affinity | 0.0245 eV | 2.391 eV |
| Density | 1540 kg/m³ | 7000 kg/m³ |
| Melting point | 841.85 °C | 301.85 °C |
| Boiling point | 1483.85 °C | -273.15 °C |
| Discovery year | 1808 | 1940 |