Potassium nitrate
Potassium nitrate is a chemical compound with the chemical formula K N O 3.This alkali metal nitrate salt is also known as Indian saltpetre (large deposits of which were historically mined in India).It is an ionic salt of potassium ions K + and nitrate ions NO 3 −, and is therefore an alkali metal nitrate.It occurs in nature as a mineral, niter (or nitre in the UK).