85
At
Astatine
[210]

General properties

Group
group 17 (halogens)
Period
period 6
Category
halogens
Standard atomic weight
-
Melting point
575 K (estimated)
Boiling point
(At₂) 503±3 K (230±3 °C)
Phase at STP
solid

Additional properties

Block
p-block
Electron configuration
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
Electrons per shell
2, 8, 18, 32, 18, 7
Electronegativity
2.2
Density
(At₂) 6.35±0.15 g/cm³ (predicted)
Oxidation states
−1, +1, +3, +5, +7
CAS Number
7440-68-8