| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024as•ta•tine (as′tə tēn′ -tin),USA pronunciation n. [Chem.]- Chemistrya rare element of the halogen family. Symbol: At;
at. no.: 85.
- Greek ástat(os) not steadfast, unstable (see astatic) + -ine2
- 1945–50
Collins Concise English Dictionary © HarperCollins Publishers:: astatine /ˈæstəˌtiːn -tɪn/ n - 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)
Etymology: 20th Century: from Greek astatos unstable (see astatic) + -ine² |