Discovered | Name | Characteristics

Astatine is in Group VIIA (Group 17) and the 6th period. Other elements in the group are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). It is more metallic than iodine.

The element was synthesized by D.R. Corson, K.R. MacKenzie, and E. Segre at the University of California in 1940. It is made by bombarding bismuth with alpha particles.

Bi + He At

Less than 0.1 microgram of the element has been prepared to date. The name comes from the Greek word astatos, meaning "unstable".

Astatine has no stable isotopes; all are radioactive. For example, 210At has a half-life of only 8.1 hours. It is also exceedingly rare. It is estimated that there is less than 1 ounce of At in the earth's crust.

What little is known of its chemistry indicates that it behaves much like the other halogens, especially iodine.