eka francium类钫
francium oxide[无化] 氧化钫
francium isotope[核] 钫同位素
Francium Carbide钫碳化物
francium compounds钫化合物
Fr Francium钫
francium compound[无化] 钫化合物
Isotopes of francium钫的同位素
N（名词） an unstable radioactive element of the alkali-metal group, occurring in minute amounts in uranium ores. Symbol: Fr; atomic no: 87; half-life of most stable isotope, 223Fr: 22 minutes; valency: 1; melting pt: 27°C; boiling pt: 677°C 钫