Atomic number:85

Group numbers:17

Period:6

Electronic configuration:[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵

Formal oxidation number:

Electronegativities:2.2

Atomic radius / pm:145

Relative atomic mass:[210]

 

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.

Density / g dm^-3:-

Molar volume / cm³mol^-1:-

Electrical resistivity / μΩcm:- (20 °C)

Thermal conductivity / W m^-1K^-1:1.7

Melting point / °C:302

Boiling point / °C:337

Heat of fusion / kJ mol^-1:23.8

Heat of vaporization / kJ mol^-1:-

Heat of atomization / kJ mol^-1:91

1st ionization energy / kJ mol^-1:-

2nd ionization energy / kJ mol^-1:-

3rd ionization energy / kJ mol^-1:-

in the atmosphere / ppm:-

in the Earth's crust / ppm:-

in the oceans / ppm:-