Activation energy
Activation energy
A reaction happens only when colliding particles have enough energy. The minimum energy needed for a successful collision is called the activation energy, EaE_{\text{a}}Ea.
Step-by-step lessons on Edexcel GCSE Chemistry 8.2.4 Activation energy and reaction profiles. Each one builds up to exam-style questions. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.