a white crystalline salt (KBr) used as a sedative and in photography
geological dating that relies on the proportions of radioactive potassium in a rock sample and its decay product, argon
a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
any of the salts of hydrobromic acid; formerly used as a sedative but now generally replaced by safer drugs
