Calcium vs Radium
| Property | Ca Calcium | Ra Radium |
|---|---|---|
| Atomic number | 20 | 88 |
| Symbol | Ca | Ra |
| Name | Calcium | Radium |
| Category | alkaline-earth-metal | alkaline-earth-metal |
| Standard Atomic Weight | 40.078 u | 226 u |
| Period | 4 | 7 |
| Group | 2 | 2 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s2 | [Rn]7s2 |
| Oxidation states | [1, 2] | [2] |
| Electronegativity (Pauling) | 1 | 0.9 |
| Electron affinity | 0.0245 eV | 0.096 eV |
| Density | 1540 kg/m³ | 5000 kg/m³ |
| Melting point | 841.85 °C | 699.85 °C |
| Boiling point | 1483.85 °C | 1139.85 °C |
| Discovery year | 1808 | 1898 |