前缀a-, 不，非。词根st, 站立，稳定。指该化学元素不稳定。
- astatine (n.)
- radioactive element, named 1947, from Greek astatos "unstable" (see astatic) + chemical suffix -ine (2). So called for its short half-life and lack of stable isotopes. "The element appears not to have a stable form and probably does not exist in nature" [Flood, "Origin of Chemical Names"].