Bimolecular elementary reactions occur when a pair of molecules or atoms collide and a single bond or multiple bonds is/are rearrange. breaking bonds requires energy; forming new bonds releases energy. which of the following statements regarding energy changes during a reaction are true? (a)the activation energy (ea) of the forward reaction is the difference between the energy of the products and the energy of the transition state. (b)if the heat of reaction, ? h, is positive, the energy of the products is lower than the energy of the reactants, and the reaction is endothermic. (c)when the activation energy is low, the reaction rate is slow. (d)two or more atoms must collide, with proper orientation, with energy greater than or equal to the activation energy for a reaction to occur. (e)increasing the concentration of reactants increases the number of collisions, and the reaction goes faster. (f)the energy of a collision between atoms or molecules must be greater than the activation energy (ea) for bonds to be broken. (g)decreasing the temperature decreases the kinetic energy of the reactants, and the reaction goes more slowly.