Francium vs Berkelium
| Property | Fr Francium | Bk Berkelium |
|---|---|---|
| Atomic number | 87 | 97 |
| Symbol | Fr | Bk |
| Name | Francium | Berkelium |
| Category | alkali-metal | actinide |
| Standard Atomic Weight | 223 u | 247 u |
| Period | 7 | 7 |
| Group | 1 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Rn]7s1 | [Rn]7s25f9 |
| Oxidation states | [1] | [2, 3, 4, 5] |
| Electronegativity (Pauling) | 0.7 | 1.3 |
| Electron affinity | 0.491 eV | -0.5 eV |
| Density | 1870 kg/m³ | 1.400000e+4 kg/m³ |
| Melting point | 26.85 °C | 1049.85 °C |
| Boiling point | -273.15 °C | -273.15 °C |
| Discovery year | 1939 | 1949 |