Translations:Potassium/9/en
Properties
Physical
Potassium is the second least dense metal after lithium. It is a soft solid with a low melting point, and can be easily cut with a knife. Potassium is silvery in appearance, but it begins to tarnish toward gray immediately on exposure to air. In a flame test, potassium and its compounds emit a lilac color with a peak emission wavelength of 766.5 nanometers.