Krypton vs Protactinium
| Property | Kr Krypton | Pa Protactinium |
|---|---|---|
| Atomic number | 36 | 91 |
| Symbol | Kr | Pa |
| Name | Krypton | Protactinium |
| Category | noble-gas | actinide |
| Standard Atomic Weight | 83.798 u | 231.03588 u |
| Period | 4 | 7 |
| Group | 18 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ar]4s23d104p6 | [Rn]7s25f26d1 |
| Oxidation states | [0, 1, 2] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 3 | 1.5 |
| Electron affinity | -1 eV | 0.123 eV |
| Density | 3.733 kg/m³ | 1.537000e+4 kg/m³ |
| Melting point | -157.36 °C | 1571.85 °C |
| Boiling point | -153.42 °C | -273.15 °C |
| Discovery year | 1898 | 1913 |