actinoids (rare earth series), namely: actinium Ac89 錒|锕, thorium Th90 釷|钍, protoactinium Pa91 鏷|镤, uranium U92 鈾|铀, neptunium Ne93 镎|镎, plutonium Pu94 鈈|钚, americium Am95 镅|镅, curium Cm96 鋦|锔, berkelium Bk97 錇|锫, californium Cf98 鐦|锎, einsteinium Es99 鎄|锿, fermium Fm100 鐨|镄, mendelevium Md101 鍆|钔, nobelium No102 鍩|锘, lawrencium Lr103 鐒|铹