Iodine vs Francium
| Property | I Iodine | Fr Francium |
|---|---|---|
| Atomic number | 53 | 87 |
| Symbol | I | Fr |
| Name | Iodine | Francium |
| Category | halogen | alkali-metal |
| Standard Atomic Weight | 126.90447 u | 223 u |
| Period | 5 | 7 |
| Group | 17 | 1 |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s24d105p5 | [Rn]7s1 |
| Oxidation states | [-1, 1, 2, 3, 4, 5, 6, 7] | [1] |
| Electronegativity (Pauling) | 2.66 | 0.7 |
| Electron affinity | 3.059 eV | 0.491 eV |
| Density | 4930 kg/m³ | 1870 kg/m³ |
| Melting point | 113.7 °C | 26.85 °C |
| Boiling point | 184.4 °C | -273.15 °C |
| Discovery year | 1811 | 1939 |