Chemical reactions require activation energy to overcome the energy barrier between reactants and products. This energy barrier is due to the requirement for breaking existing bonds in the reactants and forming new bonds in the products. Without activation energy, the reaction would not proceed as the reactant molecules would simply bounce off each other without sufficient energy to undergo bond-breaking and formation. Activation energy is necessary to provide the initial push for the reaction to occur. Once this energy barrier is overcome, the reaction can proceed on its own as the new bonds formed release energy that helps to lower the overall energy of the system. This is known as the exothermic nature of many chemical reactions. Moreover, activation energy also ensures that reactions occur at a reasonable rate. By lowering the activation energy through the use of catalysts, the reaction can proceed faster without the need for excess heat or pressure. This is crucial in industrial processes where efficiency and speed are key factors. In summary, activation energy is a fundamental concept in chemistry that governs the feasibility and rate of chemical reactions. Understanding this concept is essential for designing efficient reactions in the field of chemical engineering.