Astatine (At)
Astatine is the rarest naturally occurring element on Earth, with less than 30 grams existing at any time.
Properties of Astatine
- Atomic number
- 85
- Category
- Halogen
- Atomic mass
- 210 u
- Electron configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Melting point
- 575 K (301.85 °C)
- Boiling point
- 610 K (336.85 °C)
- Density
- 7 g/cm³
- Electronegativity (Pauling)
- 2.2
- Appearance
- Unknown, probably metallic
- Discovered by
- Dale R. Corson (1940)
Facts about Astatine
- Astatine is so rare that there's less than 30 grams of it in the entire Earth's crust!
- Astatine's name means "unstable" in Greek — it decays in hours!
- No one has ever seen astatine with the naked eye because it's so rare and radioactive!
- Astatine is being studied for use in cancer treatment!