Astatine (At), element 85 – Learn Acer periodic table

Metalloid, atomic number 85.

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.

Symbol At. Atomic mass 210.0 u. Group 17, period 6. Electron configuration [Xe] 4f14 5d10 6s2 6p5. Electrons per shell 2, 8, 18, 32, 18, 7. State at room temperature: Solid. Melting point 301.9 °C, boiling point 336.9 °C. Discovered by Dale R. Corson.

Element data from Wikipedia, CC BY-SA 3.0.

Astatine (At), element 85 – Learn Acer periodic table

Astatine

Facts