I was reading this article on exothermic reactions online: Exothermic reactions
It states that "In exothermic reactions, the products have less enthalpy than the reactants, and as a result, an exothermic reaction is said to have a negative enthalpy of reaction. This means that the energy required to break the bonds in the reactants is less than the energy released when new bonds form in the products. Excess energy from the reaction is released as heat and light."
I'm just curious, is the excess energy from the bonds being formed, or is it because of the fact that products have more potential energy than the reactants, and because of law of convervation of energy, is released as heat energy?