请输入您要查询的英文单词:

 

单词 berkelium
释义
ber·ke·li·um (bər-kēlē-əm, bûrklē-əm)
n. Symbol Bk
A synthetic transuranic radioactive element having isotopes with mass numbers from 235 to 254. Its longest-lived isotopes, Bk-247 and Bk-248, have half-lives of 1,380 years and more than 9 years, respectively; the isotope produced in greatest quantity, Bk-249, has a half-life of 330 days. Atomic number 97; melting point 996°C; specific gravity 14 (estimated); valence 3, 4. See Periodic Table.

[After Berkeley, California.]
随便看

 

英语词典包含135693条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
更新时间:2024/9/22 6:40:51