pəˈtasēəm, pōˈ-, -aas- sometimes -syəm noun
( -s )
Etymology: New Latin, from potassa + -ium
: a silver-white soft light low-melting univalent metallic element of the alkali metal group that is more reactive than sodium, oxidizing rapidly in air and reacting violently with water with the evolution of hydrogen which takes fire, that occurs abundantly in nature in combined form in minerals (as sylvite, langbeinite, and many silicates), in seawater and brines, and in plants and animals, that is prepared in the metallic state from several of its compounds by electrolysis or by reduction (as with sodium vapor) and must be preserved under kerosine or other inert hydrocarbon liquid, and that is used chiefly as a reducing agent and in synthesis — symbol K ; see element table