promethium

名词 promethium:

1. a soft silvery metallic element of the rare earth group having no stable isotope; was discovered in radioactive form as a fission product of uranium
   同义词：Pm, atomic number 61

pro.me.thi.um

n.Symbol Pm （名词）符号 Pm
A radioactive rare-earth element prepared by fission of uranium or by neutron bombardment of neodymium, having 4 isotopes with mass numbers ranging from 4 to 54 and used as a source of beta rays. Atomic number '; melting point ,'8=C; boiling point 2,4'0=C; valence 3.See table at element
钜：放射性稀土元素，由铀分裂或钛的中子爆炸而成，有十四个拥有从4到54的质量数的同位素，用作β射线源。原子序数'；熔点,'8=C；沸点2,4'0=C；原子价为3参见 element

来源：
From Prometheus
源自 Prometheus