| 释义 |
atomic number 90
基本英英
英Noun:a soft silvery-white tetravalent radioactive metallic element；isotope 232 is used as a power source in nuclear reactors；occurs in thorite and in monazite sands
Noun:
a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands |