At
Astatine
Element 85 · Halogen · Period 6, Group 17
Solid · Discovered 1940
Atomic Properties
| Atomic Number | 85 |
| Atomic Mass | 209.98715u |
| Electron Configuration | [Xe]6s2 4f14 5d10 6p5 |
| Electronegativity | 2.2Pauling |
| Atomic Radius | 202pm |
| Ionization Energy | 9.5eV |
| Electron Affinity | 2.8eV |
| Oxidation States | 7, 5, 3, 1, -1 |
Physical Properties
| Standard State | Solid |
| Melting Point | 575K |
| Density | 7g/cm³ |
| Group Block | Halogen |
| Year Discovered | 1940 |