Lanthanum vs Protactinium
| Property | La Lanthanum | Pa Protactinium |
|---|---|---|
| Atomic number | 57 | 91 |
| Symbol | La | Pa |
| Name | Lanthanum | Protactinium |
| Category | lanthanide | actinide |
| Standard Atomic Weight | 138.90547 u | 231.03588 u |
| Period | 6 | 7 |
| Group | N/A | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s25d1 | [Rn]7s25f26d1 |
| Oxidation states | [0, 1, 2, 3] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 1.1 | 1.5 |
| Electron affinity | 0.47 eV | 0.123 eV |
| Density | 6150 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | 917.85 °C | 1571.85 °C |
| Boiling point | 3463.85 °C | -273.15 °C |
| Discovery year | 1839 | 1913 |