At
85 metalloid Generated with AI
Astatine
Symbol At
Atomic Mass 210
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.
Properties
- Phase: Solid
- Density: 6.35 g/cm³
- Melting Point: 575 K
- Boiling Point: 610 K