actinium
actinium
ac.tin.i.um AHD[²k-t¹n“¶-…m] DJ[#k6t!ni8*m] KK[#k6t!ni*m]
n.SymbolAc （名词）符号Ac
A radioactive element found in uranium ores, used in equilibrium with its decay products as a source of alpha rays. Its longest lived isotope is Ac 227 with a half-life of 21.7 years. Atomic number 89; melting point 1,050&9{=}C; boiling point (estimated) 3,200&9{=}C; specific gravity (calculated) 10.07; valence 3.See table atelement
锕：一种在铀矿中发现的放射性元素，作为阿尔法射线能源增入点用于与其衰变产物的平衡过程中，其最长的活同位素是半衰期为21.7年的锕227。原子序数为89；熔点为1,050摄氏度；（估计的）沸点为3,200摄氏度；（计算出的）比重为10.07；原子价为3参见element
