Radium
01
(chemistry) a rare, silvery-white, radioactive metallic element in Group 2 of the periodic table that does not occur freely in nature
语法信息
例子
Radium was once used in luminous paints for watch dials and clocks.
(chemistry) a rare, silvery-white, radioactive metallic element in Group 2 of the periodic table that does not occur freely in nature
