Oxygen vs Protactinium
| Property | O Oxygen | Pa Protactinium |
|---|---|---|
| Atomic number | 8 | 91 |
| Symbol | O | Pa |
| Name | Oxygen | Protactinium |
| Category | nonmetal | actinide |
| Standard Atomic Weight | 15.9994 u | 231.03588 u |
| Period | 2 | 7 |
| Group | 16 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [He]2s22p4 | [Rn]7s25f26d1 |
| Oxidation states | [-2, -1, 0, 1, 2] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 3.44 | 1.5 |
| Electron affinity | 1.4611 eV | 0.123 eV |
| Density | 1.429 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | -218.79 °C | 1571.85 °C |
| Boiling point | -182.95 °C | -273.15 °C |
| Discovery year | 1771 | 1913 |