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 WordNet 3.0 & Open English WordNet

Potassium is a chemical element; it has symbol K and atomic number 19. Wikipedia

Symbol K, a chemical element Wikipedia Disambiguation

chemical element with symbol K and atomic number 19 Wikidata

A silvery-white metallic alkali metal element with the symbol K and atomic number 19, occurs principally as component of sea water and in several minerals like carnallite, polyhalite and sylvite. It is being used as fertilizer as either the chloride, sulfate or carbonate. OmegaWiki

A soft, waxy, silvery reactive metal that is never found unbound in nature; an element (symbol K) with an atomic number of 19 and atomic weight of 39.0983. The symbol is derived from the Latin kalium. Wiktionary