POTASSIUM

The potassium is a chemical element of the periodic table which symbol is K (of the Latin Kalium and the name, of the Englishman pot ashes, ashes), whose atomic number is 19. It is an alkaline metal, silver white that abounds in the nature, in the elements related to the salty water and other minerals. It oxidizes rapidly in the air, is very a reagent, specially in water, and looks like chemically the sodium. It is the most light fifth and frivolous metal.
The potassium metal is used in photoelectric cells and the chloride and the nitrate they use as fertilizers.
The potassium, of the Dutchman pottasche, ash of pot, name with which Humphry Davy baptized it on having discovered it in 1807, was the first metallic element isolated by electrolysis.

Information obtained of www.wikipedia.org