GCSE Chemistry
Energy Changes
Energy Changes is a core strand in Chemistry. Work through the topics below in any order, or follow your course — each guide includes explanations, common mistakes and exam-style practice.
Topic guides
Exothermic & Endothermic
Chemical reactions involve energy changes.
Open guideReaction Profiles
A reaction profile, or energy level diagram, shows the energy changes that occur during a chemical reaction.
Open guideBond Energy Calculations
Bond energy (or bond enthalpy) is the amount of energy required to break one mole of a specific covalent bond.
Open guideCells & Batteries
A simple electrochemical cell, or battery, consists of two different metals connected by a wire and dipped in an electrolyte.
Open guide
Revision strategy
Students often slip on the details explained in our guides — read the “common mistakes” section in each topic.
- Alternate between reading a guide and doing timed questions — don’t only re-read notes.
- Return to this hub anytime; new guides appear automatically as we publish them.