Astatine (At) — Element 85

85 At 210

Astatine

Element 85 · 210 u · p-block

nonmetal

The rarest naturally occurring element on Earth — at most 25g exists at any time. All isotopes are radioactive.

Phase (STP)

Solid

Melting Point

302 °C

Boiling Point

337 °C

Density

7 g/cm³

Electronegativity

2.2

Atomic Radius

—

Ionization Energy

—

Electron Affinity

270 kJ/mol

Discovered

1940 · Dale R. Corson

Electron Configuration

[Xe] 4f14 5d10 6s2 6p5