In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is defined as the
(1) activation energy
(2) ionization energy
(3) heat of reaction
(4) heat of vaporization

Answer: (1) activation energy

Explanation:-

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

Ionization energy is the energy required to remove the most loosely bound electron from an isolated gaseous atom.

Heat of reaction is the energy released or absorbed during the course of the reaction.

Heat of vaporization is the energy required to convert 1 mole of liquid substance to gaseous form.