The Rarest Element on Earth: Astatine

Astatine is the rarest naturally occurring element on Earth, with an estimated abundance of only 20 grams (0.7 oz) in the entire Earth's crust. It is a highly radioactive, colorless, and odorless gas with the atomic number 112. Astatine is a member of the halogen family and is the heaviest known halogen element.

Astatine was first synthesized in 1940 by a team of scientists at the University of California, Berkeley, who bombarded bismuth with alpha particles to produce the element. Since then, only a few milligrams of astatine have been produced, and it has been studied primarily in the context of nuclear physics and chemistry.

Astatine is highly radioactive and decays rapidly into other elements, emitting alpha, beta, and gamma radiation. Its half-life, which is the time it takes for half of the element to decay, is only a few hours, making it extremely difficult to work with and study. As a result, very little is known about the chemical properties of astatine, and it is not believed to have any practical applications due to its extreme radioactivity and short half-life.