Recall that we can calculate the enthalpy of a reaction by comparing the atomization energies of the reactants and products. (This is the same idea as when we calculated enthalpies of reaction using s...Recall that we can calculate the enthalpy of a reaction by comparing the atomization energies of the reactants and products. (This is the same idea as when we calculated enthalpies of reaction using standard enthalpies of formation.) If the product has stronger bonds than the reactants, the reaction is likely to be exothermic, and exothermic reactions often go forward.