potassium
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
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
potassium
[pə′tas·ē·əm] (chemistry)
A chemical element, symbol K, atomic number 19, atomic weight 39.0983; an alkali metal. Also known as kalium.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.