Astatine - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  At

Relative atomic mass: [210]

English: Astatine
French: Astate
Croatian: Astat
German: Astat
Italian: Astato
Spanish: Astato

Atomic number: 85
Group numbers: 17
Period: 6
Standard state (20 °C): solid

Discovery: 1940 Emilio Segré, Dale Raymond Corson, Kenneth Ross Mackenzie (US)

Astatine was discovered by Emilio Segré, Dale Raymond Corson, and Kenneth Ross Mackenzie (US) in 1940. The origin of the name comes from the Greek word 'astatos' meaning 'unstable'. It is a unstable, radioactive member of the halogen group. Astatine does not occur in nature, it is similar to iodine. Astatine is produced by bombarding bismuth with alpha particles. Since its isotopes have such short half-lives there are no commercially significant compounds of astatine.

Electronic configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
Formal oxidation number: 
Atomic radius: 145 pm

Electronegativities: 2.2
Thermal conductivity: 1.7 W/(m K)
Electrical resistivity (20 °C): - μΩcm

Melting point: 302 °C
Boiling point: 337 °C

Heat of fusion: 23.8 kJ/mol
Heat of vaporization: - kJ/mol
Heat of atomization: 91 kJ/mol