Krypton vs Roentgenium
| Property | Kr Krypton | Rg Roentgenium |
|---|---|---|
| Atomic number | 36 | 111 |
| Symbol | Kr | Rg |
| Name | Krypton | Roentgenium |
| Category | noble-gas | transition-metal |
| Standard Atomic Weight | 83.798 u | 281 u |
| Period | 4 | 7 |
| Group | 18 | 11 |
| Block | p | s |
| Phase at STP | gas | N/A |
| Electron configuration | [Ar]4s23d104p6 | [Rn] 7s2 5f14 6d9(predicted) |
| Oxidation states | [0, 1, 2] | [-1, 1, 3, 5] |
| Electronegativity (Pauling) | 3 | N/A |
| Electron affinity | -1 eV | 1.6 eV |
| Density | 3.733 kg/m³ | 2.870000e+4 kg/m³ |
| Melting point | -157.36 °C | -273.15 °C |
| Boiling point | -153.42 °C | -273.15 °C |
| Discovery year | 1898 | 1994 |