Krypton vs Radium
| Property | Kr Krypton | Ra Radium |
|---|---|---|
| Atomic number | 36 | 88 |
| Symbol | Kr | Ra |
| Name | Krypton | Radium |
| Category | noble-gas | alkaline-earth-metal |
| Standard Atomic Weight | 83.798 u | 226 u |
| Period | 4 | 7 |
| Group | 18 | 2 |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ar]4s23d104p6 | [Rn]7s2 |
| Oxidation states | [0, 1, 2] | [2] |
| Electronegativity (Pauling) | 3 | 0.9 |
| Electron affinity | -1 eV | 0.096 eV |
| Density | 3.733 kg/m³ | 5000 kg/m³ |
| Melting point | -157.36 °C | 699.85 °C |
| Boiling point | -153.42 °C | 1139.85 °C |
| Discovery year | 1898 | 1898 |