All chemical elements

Symbol

At

Atomic number

85

Chemical property

Metalloid

Origin o the name

the Greek astatos, 'unstable'

Group

17

Period

6

Density (g/cm³)

7

Melting point (K)

575

Boiling point (K)

610

Electro-negativity

2.2

Abundance in earth's crust (mg/kg)

0