Potassium is a soft, silver-white metal.
Physically and chemically it resembles the other alkali metals in group Ia of the periodic table . It is extremely reactive, more so than sodium. It combines so readily with oxygen that it is usually stored submerged in kerosene or some other hydrocarbon, out of contact with air. It reacts violently with water to form potassium hydroxide, KOH, releasing hydrogen, which usually ignites. It reacts with many organic compounds.