In a chemical change, reactants are converted into products. This change is brought about by one or more methods, such that heat changes remain constant, irrespective of whichever method is followed. This statement is according to
the principle of conservation of energy. It states that energy cannot be created or destroyed, but it can be converted from one form to another. In a chemical change, the energy in the reactants is converted into different forms of energy in the products, such as heat, light, or electrical energy. The total amount of energy before and after the reaction remains constant.
