Astatine |
Symbol | At |
---|---|
Latin name | Astatum |
Atomic number | 85 |
Period | 6 |
Element category | Halogens |
Relative atomic mass | 209.9871 |
Group | VII.A |
Electronegativity | 2.2 |
Oxidation numbers | -1, 1, 3, 5, 7 |
Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p5 |
State | Solid |
Melting point [°C] | 302 |
Boiling point [°C] | 330 |
Atomic radius [pm] | 127 |
Thermal conductivity [W m-1K-1] | 1.7 |
Discovery | 1940 |
1.st ionization energy [eV] | 9.5 |
Stable isotopes | 0 |
Unstable isotopes | 21 |