Terbium vs Protactinium
| Property | Tb Terbium | Pa Protactinium |
|---|---|---|
| Atomic number | 65 | 91 |
| Symbol | Tb | Pa |
| Name | Terbium | Protactinium |
| Category | lanthanide | actinide |
| Standard Atomic Weight | 158.92535 u | 231.03588 u |
| Period | 6 | 7 |
| Group | N/A | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Xe]6s24f9 | [Rn]7s25f26d1 |
| Oxidation states | [0, 1, 2, 3, 4] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | N/A | 1.5 |
| Electron affinity | 1.124 eV | 0.123 eV |
| Density | 8230 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | 1355.85 °C | 1571.85 °C |
| Boiling point | 3229.85 °C | -273.15 °C |
| Discovery year | 1843 | 1913 |