Oxygen vs Radium
| Property | O Oxygen | Ra Radium |
|---|---|---|
| Atomic number | 8 | 88 |
| Symbol | O | Ra |
| Name | Oxygen | Radium |
| Category | nonmetal | alkaline-earth-metal |
| Standard Atomic Weight | 15.9994 u | 226 u |
| Period | 2 | 7 |
| Group | 16 | 2 |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [He]2s22p4 | [Rn]7s2 |
| Oxidation states | [-2, -1, 0, 1, 2] | [2] |
| Electronegativity (Pauling) | 3.44 | 0.9 |
| Electron affinity | 1.4611 eV | 0.096 eV |
| Density | 1.429 kg/m³ | 5000 kg/m³ |
| Melting point | -218.79 °C | 699.85 °C |
| Boiling point | -182.95 °C | 1139.85 °C |
| Discovery year | 1771 | 1898 |