[puh-tas-ee-uh m] /pəˈtæs i əm/
a silvery-white metallic element that oxidizes rapidly in the air and whose compounds are used as fertilizer and in special hard glasses. Symbol: K; atomic weight: 39.102; atomic number: 19; specific gravity: 0.86 at 20°C.
a light silvery element of the alkali metal group that is highly reactive and rapidly oxidizes in air; occurs principally in carnallite and sylvite. It is used when alloyed with sodium as a cooling medium in nuclear reactors and its compounds are widely used, esp in fertilizers. Symbol: K; atomic no: 19; atomic wt: 39.0983; valency: 1; relative density: 0.862; melting pt: 63.71°C; boiling pt: 759°C
metallic element, 1807, coined by English chemist Sir Humphrey Davy (1778-1829) from Modern Latin potassa, Latinized form of potash (q.v.). Davy first isolated it from potash. Symbol K is from Latin kalium “potash,” from Arabic al-qaliy “the ashes, burnt ashes” (see alkali).
potassium po·tas·si·um (pə-tās’ē-əm)
A soft, highly or explosively reactive metallic element that occurs in nature only in compounds and is found in or converted to a wide variety of salts used especially in fertilizers and soaps. Atomic number 19; atomic weight 39.098; melting point 63.28°C; boiling point 759°C; specific gravity 0.862; valence 1. Also called kalium.
A soft, highly reactive, silvery-white metallic element of the alkali group occurring in nature only in compounds. It is essential for the growth of plants and is used especially in fertilizers and soaps. Atomic number 19; atomic weight 39.098; melting point 63.65°C; boiling point 774°C; specific gravity 0.862; valence 1. See Periodic Table.
potassium-40 n. A naturally occurring beta-emitting radioactive isotope of potassium having a half-life of 1.3 billion years; it is the chief source of natural radioactivity of living tissue.
potassium-42 n. An artificially produced beta-emitting isotope of potassium having a half-life of 12.36 hours; it is used as a radioactive tracer in studies of potassium distribution in bodily fluids.
potassium-43 n. An artificially produced beta-emitting isotope of potassium having a half-life of 22 hours; it is used as a radioactive tracer in myocardial perfusion studies.
noun, Chemistry. 1. a white, crystalline, deliquescent, water-soluble powder, KC 2 H 3 O 2 , used chiefly as a reagent in analytical chemistry.