What is activation energy?
The minimum energy colliding particles need in order to react
The energy released when a catalyst speeds up a reaction
The average kinetic energy of particles before they collide
The total energy stored in the products of the reaction
94 exam-style questions on Edexcel GCSE Chemistry 8.2 Heat energy changes in chemical reactions, covering 8.2.1 Exothermic and endothermic changes, 8.2.2 Bond breaking, bond making and overall energy change, 8.2.3 Calculating energy change from bond energies, and 8.2.4 Activation energy and reaction profiles. Each one has a worked solution and a mark scheme showing where the marks go.