Krypton vs Actinium
| Property | Kr Krypton | Ac Actinium |
|---|---|---|
| Atomic number | 36 | 89 |
| Symbol | Kr | Ac |
| Name | Krypton | Actinium |
| Category | noble-gas | actinide |
| Standard Atomic Weight | 83.798 u | 227 u |
| Period | 4 | 7 |
| Group | 18 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ar]4s23d104p6 | [Rn]7s26d1 |
| Oxidation states | [0, 1, 2] | [3] |
| Electronegativity (Pauling) | 3 | 1.1 |
| Electron affinity | -1 eV | 0.35 eV |
| Density | 3.733 kg/m³ | 1.007000e+4 kg/m³ |
| Melting point | -157.36 °C | 1050.85 °C |
| Boiling point | -153.42 °C | 3197.85 °C |
| Discovery year | 1898 | 1899 |