Radium
01
(chemistry) a rare, silvery-white, radioactive metallic element in Group 2 of the periodic table that does not occur freely in nature
文法情報
例
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
