astatine

[ as-tuh-teen, -tin ]

noun

, Chemistry.

1. a rare element of the halogen family. : At; : 85.

astatine

/ -tɪn; ˈæstəˌtiːn /

noun

1. a radioactive element of the halogen series: a decay product of uranium and thorium that occurs naturally in minute amounts and is artificially produced by bombarding bismuth with alpha particles. Symbol: At; atomic no: 85; half-life of most stable isotope, ²¹⁰At: 8.1 hours; probable valency: 1,3,5, or 7; melting pt: 302°C; boiling pt: 337°C (est)

astatine

/ ăs′tə-tēn′ /

1. A highly unstable, rare, radioactive element that is the heaviest of the halogen elements. Its most stable isotope 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.
2. See Periodic Table

Word History and Origins

Origin of astatine¹

1945–50; < Greek ástat ( os ) not steadfast, unstable ( astatic ) + -ine ²

Word History and Origins

Origin of astatine¹

C20: from Greek astatos unstable (see astatic ) + -ine ²