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.

plural of potassium

(inorganic chemistry) The salt KNbO₃; its crystals have a large nonlinear optical coefficient, and it find use in the manufacture of lasers; nanowires of the substance have been used to produce tunable coherent light.

(inorganic chemistry) The potassium salt of hydrochloric acid, KCl; it is used as a fertilizer, and in lethal injections

(inorganic chemistry) The alkaline salt K₂CO₃, that is the major constituent of potash; it is used in the production of glass and some soaps.

(inorganic chemistry) The alkaline base KOH, once known as caustic potash; it has a number of industrial uses, including the manufacture of bleach.

A particular artificial sweetener.

The artificial sweetener, potassium 6-methyl-2,2-dioxo-oxathiazin-4-olate

(obsolete, inorganic chemistry) potassium bromide

(biology) A small pore in a cell membrane that is selective to potassium ions and has several regulatory functions.