Difference between Potash and Potassium

What is the difference between Potash and Potassium?

Potash as a noun is the water-soluble part of the ash formed by burning plant material; used for making soap, glass and as a fertilizer while Potassium as a noun is a soft, waxy, silvery reactive metal that is never found unbound in nature; an element (symbol k) with an atomic number of 19 and atomic weight of 39.0983. the symbol is derived from the latin kalium.

We hope you now know whether to use Potash or Potassium in your sentence.