Potassium is the second lightest metal, it is a soft solid with a low melting point, and can be easily cut, even with just a knife. Potassium is silvery but it begins to tarnish toward gray immediately.
Potassium finds most of its use as fertilizer but not as pure potassium. It doesn't have much use as a metal or an use as an alloy.
Potassium has a melting temperature of 146F (63.3C).