In this relation potassium chlorate decomposes or splits into KCl and O2 products hence it is called decomposition reaction.
Energy is needed for this decomposition hence it is an endothermic reaction.
2 KClO3 = 2KCl + 3O2
In the endothermic reaction the reactants absorbs energy from surrounding to form product
When a reactant decompose or split into two or more products are called decomposition reaction. for example the decomposition of calcium carbonate into calcium oxide and carbon dioxide
