Potassium

Potassium is a soft, silvery-white alkali metal. Like other alkali metals, it readily loses its outermost electron to form positively charged ions. It reacts so readily with water and oxygen that it occurs naturally in compounds rather than as a free metal. Potassium is present in rock-forming minerals, seawater and salt deposits. Industry obtains potassium salts mainly from mined potash deposits, including the mineral sylvite, and from concentrated salty waters called brines. Potassium metal is produced by reacting potassium chloride with sodium in an industrial process. Most potassium salts are used in fertilizers to replace nutrients removed from soil by crops. In foods and living cells, potassium is present as ions, not pieces of metal. These ions help nerves send signals, making potassium essential to life.