a radioactive chemical element, one of the halogens, formed from bismuth when it is bombarded by alpha particles: it resembles iodine in its chemical properties: symbol, At; at. no. 85
Origin of astatine; from Classical Greek astatos, unstable + -ine
A highly unstable radioactive element, the heaviest of the halogen group, that resembles iodine in solution. Its longest lived isotope has a mass number of 210 and has a half-life of 8.3 hours. Atomic number 85; melting point 302°C; boiling point 337°C; valence probably 1, 3, 5, 7. See Periodic Table.
Origin of astatineGreek astatos, unstable; see astasia + –ine2.
- A highly radioactive chemical element (symbol At), one of the halogens, with atomic number 85.
- in a state
From Ancient Greek ἄστατος (astatos, “unstable”) + -ine.