Strontium vs Protactinium
| Property | Sr Strontium | Pa Protactinium |
|---|---|---|
| Atomic number | 38 | 91 |
| Symbol | Sr | Pa |
| Name | Strontium | Protactinium |
| Category | alkaline-earth-metal | actinide |
| Standard Atomic Weight | 87.62 u | 231.03588 u |
| Period | 5 | 7 |
| Group | 2 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s2 | [Rn]7s25f26d1 |
| Oxidation states | [1, 2] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 0.95 | 1.5 |
| Electron affinity | 0.052 eV | 0.123 eV |
| Density | 2640 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | 776.85 °C | 1571.85 °C |
| Boiling point | 1381.85 °C | -273.15 °C |
| Discovery year | 1792 | 1913 |