Activation Barrier Theory

Activation Barrier Theory explains how chemical reactions occur by requiring reactants to gain enough energy to overcome an energy barrier, called the activation energy. Imagine reactants as travelers needing a certain push to cross a mountain pass (the barrier) to reach the product side. Only when they acquire sufficient energy—through heat or other means—can the reaction proceed. This concept helps us understand why some reactions happen quickly while others are slow or require energy input. Essentially, the activation barrier is the energy hurdles molecules must clear to transform into products.