Fiducia TogetherConservation of energy in reactions
Energy is transferred, not created, in chemistry as everywhere else.
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.
What it is
In a chemical reaction the total energy of the universe is unchanged; energy is transferred between the chemical store and the surroundings.
Where it applies
GCSE chemistry and combined science.
How it works
This is why an exothermic reaction warms its surroundings: the energy has moved out of the chemical store, not vanished from it.
It links directly to the physics treatment of energy stores and transfers.
How to use it in your work
Use the language of stores and transfers, matching the physics vocabulary.
Never say energy is 'produced' or 'used up' in a reaction. It is transferred.
Where to get help
Your teacher and your board's specification and mark scheme.
Revise this with a song
These are ours. We write revision songs because a lot of people remember a tune when they cannot remember a page, and because revising out loud in the kitchen beats staring at a highlighter.
- The Chemistry Song The GCSE chemistry specification, set to music.
Where to read more
Last reviewed 2026-08-28 by Fiducia Together · Next review due 2027-08-28
Please note: This page explains a word or a process in education. It is general information about the system, the law and the guidance in England — not advice about your child, your school or your exam. If a decision is going against you, get advice from one of the free services we link to before you agree to anything or miss a deadline. If you are revising, check your own exam board's specification: boards word things differently and yours is the one that marks you.