If someone could provide a mnemonic or a simple way to write this out it would be extremely helpful. This deals with determining the oxidation state of elements. A "free" element A monoatomic ion Part of an ionic or covalent compound Part of a polyatomic ion I know that H and O's numbers can change depending on how they are bound to other elements, but usually H is +1. However a more simple way to memorize these would be helpful if anyone knows.