1.【化】铹
1.a short-lived radioactive metallic element.
1.Actinide: Any of the series of 15 consecutive chemical elements in the periodic table from actinium to lawrencium (atomic numbers 89-103).
锕系:周期表中从锕到铹(原子序数89~103)的十五个依次排列的一组化学元素。