A rare, radioactive chemical element (symbol At, atomic number 85) belonging to the halogen group, existing only in tiny amounts in nature.
From Greek 'astatos' (unstable) plus the chemical suffix '-ine.' Named in 1940 by scientists who recognized how unstable this new element was.
Astatine is so rare and radioactive that scientists have never actually seen pure astatine—every atom they make decays in minutes, making it one of chemistry's most elusive elements.
Complete word intelligence in one call. Free tier — 50 lookups/day.