Oxygen vs Francium
| Property | O Oxygen | Fr Francium |
|---|---|---|
| Atomic number | 8 | 87 |
| Symbol | O | Fr |
| Name | Oxygen | Francium |
| Category | nonmetal | alkali-metal |
| Standard Atomic Weight | 15.9994 u | 223 u |
| Period | 2 | 7 |
| Group | 16 | 1 |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [He]2s22p4 | [Rn]7s1 |
| Oxidation states | [-2, -1, 0, 1, 2] | [1] |
| Electronegativity (Pauling) | 3.44 | 0.7 |
| Electron affinity | 1.4611 eV | 0.491 eV |
| Density | 1.429 kg/m³ | 1870 kg/m³ |
| Melting point | -218.79 °C | 26.85 °C |
| Boiling point | -182.95 °C | -273.15 °C |
| Discovery year | 1771 | 1939 |