Astatine

| Introduction | History | Other Periodic Tables | Back |

Symbol:

At

Atomic Number:

85

Relative Atomic Mass:

209.9871 g mol^-1

Natural Abundance in Lithosphere, hydrosphere and atmosphere:

3 x 10^-24% (mass fraction)

Electron Configuration:

[Xe]4f¹⁴5d¹⁰6s²6p⁴

Oxidation States:

VII, V, III, I, -I

Atomic Radius:

145pm

Ionic Radius:

62pm (for +7 oxidation state)

Melting Point:

302°C

First Ionisation Energy:

9.5 eV

Electronegativity (Allred and Rochow):

2.0

Number of Natural Isotopes:

4