Potassium is a chemical element with symbol K and atomic number 19. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals.

Atomic Weight:  39.0983
Density:        0.856 g/cm3
Melting Point:  .38 °C
Boiling Point:  759 °C