Astatine
Reactive Nonmetal
Astatine (At) is a chemical element with atomic number 85, classified as a reactive nonmetal. At room temperature it is a solid. It was discovered in 1940 by Dale R. Corson et al..
Properties
- Atomic number
- 85
- Atomic mass
- 210 u
- Category
- Reactive Nonmetal
- Group
- 17
- Period
- 6
- Block
- p-block
- Electron configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Phase at STP
- Solid
- Density
- 7 g/cm³
- Melting point
- 575 K (301.9 °C)
- Boiling point
- 610 K (336.9 °C)
- Electronegativity
- 2.2
- Atomic radius
- 127 pm
- Ionization energy
- 9.318 eV
- Discovery
- 1940 · Dale R. Corson et al.
Common uses
Cancer treatment research, radioactive tracers
Did you know?
Rarest naturally occurring element - less than 1 ounce exists on Earth.
Experiment with the elements
Astatine doesn't form any compounds in our lab yet, but the periodic table sandbox lets you combine dozens of other real elements into real compounds — water, table salt, ammonia and many more — with their true chemical formulas.