Flexi Says: A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances. The general form of a decomposition reaction is AB→A+B The most straightforward decomposition reaction is when a binary compound decomposes into its elements. For example, mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas: 2HgO(s)→2Hg(l)+O2(g). There are three types of decomposition reactions: thermal, electrolytic, and photolytic decomposition reactions in which heat, electricity, and light respectively are used for the decomposition of the reactants.
