AQA GCSE Chemistry Paper 2 Practice Exam 2026 – Complete Study Resource

Activation energy is defined as the minimum amount of energy that particles must possess in order to successfully collide and react to form products. This concept is crucial in understanding how chemical reactions occur, as not all collisions between molecules result in a reaction. In order for a reaction to take place, the colliding particles must have enough energy to overcome a barrier, which is represented by the activation energy.

This energy is essential for breaking bonds in the reactants, allowing new bonds to form in the products. Consequently, the higher the activation energy, the more energy is required to initiate the reaction, which can affect the reaction rate. In essence, activation energy is a threshold that must be surpassed for the reaction to proceed, making it a fundamental concept in both chemistry and thermodynamics.