Iodine vs Astatine
| Property | I Iodine | At Astatine |
|---|---|---|
| Atomic number | 53 | 85 |
| Symbol | I | At |
| Name | Iodine | Astatine |
| Category | halogen | halogen |
| Standard Atomic Weight | 126.90447 u | 210 u |
| Period | 5 | 6 |
| Group | 17 | 17 |
| Block | p | p |
| Phase at STP | solid | solid |
| Electron configuration | [Kr]5s24d105p5 | [Xe]6s24f145d106p5 |
| Oxidation states | [-1, 1, 2, 3, 4, 5, 6, 7] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 2.66 | 2.2 |
| Electron affinity | 3.059 eV | 2.391 eV |
| Density | 4930 kg/m³ | 7000 kg/m³ |
| Melting point | 113.7 °C | 301.85 °C |
| Boiling point | 184.4 °C | -273.15 °C |
| Discovery year | 1811 | 1940 |