85 At 210
Astatine
metalloid
Properties
- Atomic number
- 85
- Atomic mass
- 210 u
- Category
- metalloid
- Group
- 17
- Period
- 6
- Block
- p-block
- State (room temp)
- Solid
- Outer-shell electrons
- 7
- Electronegativity
- 2.2 (Pauling)
- Density
- 6.35 g/cm³
- Melting point
- 301.85 °C
- Boiling point
- 336.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁵
Noble-gas shorthand: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
Electrons per shell: 2, 8, 18, 32, 18, 7 — that's 7 in the outermost shell.
About Astatine
Astatine is a very rare radioactive chemical element with the chemical symbol At and atomic number 85. It occurs on Earth as the decay product of various heavier elements. All its isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.
- Discovered by Dale R. Corson
- Appearance: unknown, probably metallic
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.