Potassium nitrate Potassium nitrate Potassium nitrate is a chemical compound with the chemical formula KNO. It is an ionic salt of potassium ions K and nitrate ions NO, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter. It is a source of nitrogen, from which it derives its name. Potassium nitrate is one of several nitrogen-containing compounds collectively referred to as saltpeter or saltpetre. Major uses of potassium nitrate are in fertilizers, tree stump removal, rocket propellants and fireworks. It is one of the major constituents of gunpowder (black powder) and has been used since the
Period 6 element element with the symbol Po and atomic number 84, discovered in 1898 by Marie Skłodowska-Curie and Pierre Curie. A rare and highly radioactive element, polonium is chemically similar to bismuth and tellurium, and it occurs in uraniumores. Polonium has been studied for possible use in heating spacecraft. As it is unstable, all isotopes of polonium are radioactive. There is disagreement as to whether polonium is a post-transition metal or metalloid. Astatine is a radioactive chemical element with the symbol At and atomic number 85. It occurs on the Earth only as the result of decay of heavier elements, and decays