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 oC): solid

Discovery: 1940 Emilio Segre, Dale Raymond Corson, Kenneth Ross Mackenzie (US)
Astatine was discovered by Emilio Segre, 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 oC): - microOhm cm

Melting point: 302 oC
Boiling point: 337 oC

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

84Po <= 85At => 86Rn


ASCII Periodic Table of the Elements
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29 Aug. 2017
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