- Atomic Radius (Å)
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.
85
Atomic Number
210 u
Atomic Mass
575.15 K
Melting Point
610 K
Boiling Point
6.35 g/cm³
Density
1.4 Å
Atomic Radius
1.5 Å
Covalent Radius
2.2
Electronegativity
9.3 eV
First Ionization Energy
233
Electron Affinity
6
Number of Shells
7
Electron Valency
2, 8, 18, 32, 18, 7
Electron Shell Occupations
null J/g
Specific Heat