网站首页  词典首页

请输入您要查询的词汇:

 

词汇 protactinium
释义 pro·tac·tin·i·um AHD[prō'tăk-tĭnʹē-əm] D.J.[ˌprəʊtækˈtɪniːəm]K.K.[ˌprotækˈtɪniəm]n.Symbol Pa (名词)符号 Pa
  1. A rare, extremely toxic, radioactive element chemically similar to uranium, having 13 known isotopes, the most common of which is protactinium 231 with a half-life of 32,480 years. Atomic number 91; melting point 1,230°C; specific gravity 15.37; valence 4, 5. See table at element 镤:一种稀有的、剧毒放射性元素,在化学性质上与铀相似。有十三个已知的同位素,其中最常见的是半衰期为32,480年的镤231。原子序数为91;熔点1,230°C;比重15.37;原子价4, 5 参见 element
Etymology语源
    1. prot(o)- prot(o)-
    1. actinium [so called because it disintegrates into actinium] actinium [它被这样取名是由于它分裂成锕]
随便看

 

烛光网英语在线翻译词典收录了166908条英语词汇在线翻译词条,基本涵盖了全部常用英语词汇的中英文双语翻译及用法,是英语学习的有利工具。

 

Copyright © 2000-2024 Clmag.com All Rights Reserved 更新时间:2024/12/23 11:51:43