Chlorine vs Astatine
| Property | Cl Chlorine | At Astatine |
|---|---|---|
| Atomic number | 17 | 85 |
| Symbol | Cl | At |
| Name | Chlorine | Astatine |
| Category | halogen | halogen |
| Standard Atomic Weight | 35.4515 u | 210 u |
| Period | 3 | 6 |
| Group | 17 | 17 |
| Block | p | p |
| Phase at STP | gas | solid |
| Electron configuration | [Ne]3s23p5 | [Xe]6s24f145d106p5 |
| Oxidation states | [-1, 1, 2, 3, 4, 5, 6, 7] | [-1, 1, 3, 5, 7] |
| Electronegativity (Pauling) | 3.16 | 2.2 |
| Electron affinity | 3.6127 eV | 2.391 eV |
| Density | 3.214 kg/m³ | 7000 kg/m³ |
| Melting point | -101.5 °C | 301.85 °C |
| Boiling point | -34.04 °C | -273.15 °C |
| Discovery year | 1774 | 1940 |