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Conservation Of Mass - GCSE Chemistry Definition

Reviewed by: Philippa Platt

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The conservation of mass is a key principle in chemistry that states that mass cannot be created or destroyed in a closed system during a chemical reaction. This means that the total mass of the reactants— the substances you start with— will be the same as the total mass of the products— the substances you end up with.

For example, if you burn wood in a sealed container, the mass of the ash, gases, and any other products will equal the mass of the original wood and oxygen. This principle is important for balancing chemical equations and understanding how reactions occur.

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Philippa Platt

Reviewer: Philippa Platt

Expertise: Chemistry Content Creator

Philippa has worked as a GCSE and A level chemistry teacher and tutor for over thirteen years. She studied chemistry and sport science at Loughborough University graduating in 2007 having also completed her PGCE in science. Throughout her time as a teacher she was incharge of a boarding house for five years and coached many teams in a variety of sports. When not producing resources with the chemistry team, Philippa enjoys being active outside with her young family and is a very keen gardener

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