In chemistry, hydroxide is the name for the diatomic anion OH−, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest and most pervasive diatomic ions known. Inorganic compounds that contain the hydroxyl group are referred to as hydroxides. Alkali metal (Li+, Na+, K+) and alkaline earth (Mg2+, Ca2+, Ba2+) salts containing hydroxide are common bases. Common hydroxides include: Sodium hydroxide, NaOH Potassium hydroxide, KOH Calc… (More on Hydroxide)