| 释义 |
fran·ci·um AHD[frănʹsē-əm] D.J.[ˈfrænsiːəm]K.K.[ˈfrænsiəm]n.Symbol Fr （名词）符号 Fr - An extremely unstable radioactive element of the alkali metals, produced artificially from actinum or thorium, having approximately 19 isotopes, the most stable of which is Fr 223 with a half-life of 21 minutes. Atomic number 87; valence 1. See table at element 钫：从碱金属锕或钍中人工提炼出的一种极不稳定的放射线元素，约有19种同位素，其中最稳定的是半衰期为21分钟的Fr223。原子序数为87；化合价为1 参见 element
- After France 源自 France
|