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      Three types of chemical reaction

      Lesson details

      Learning outcome

      I can use chemical equations to identify and describe oxidation, decomposition and precipitation reactions.

      Key learning points

      1. In a chemical reaction the + symbol can be read as ‘and’ and the arrow as ‘changes into’.
      2. In an oxidation reaction a reactant combines with oxygen.
      3. In a decomposition reaction a reactant splits into two or more new substances.
      4. In a precipitation reaction an insoluble salt is formed.

      Keywords

      • Chemical equation - A chemical equation describes a reaction, indicating the reactants and products.

      • Oxidation - Oxidation is a type of reaction in which oxygen bonds to elements of the reactants.

      • Decomposition - Decomposition is a type of reaction in which a reactant compound breaks down into two or more products.

      • Precipitation - A reaction in which an insoluble salt forms from two solutions is called a precipitation reaction.

      Common misconception

      Pupils *very* easily confuse different types of reactions.

      Spend time developing ways to help pupils remember the differences and regularly challenge them to explain why one reaction is the type it is.

      Teacher tip

      Create a circus of reactions during which pupils write the chemical equation to represent it and identify the type of reaction it is.

      Licence

      This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0
      except where otherwise stated. See Oak's terms & conditions
      (Collection 2).

      Lesson video

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      Prior knowledge starter quiz

      6 Questions

      Q1.
      Which of the following are compounds?

      O₂
      Correct answer: NaCl
      Potassium
      Correct answer: Water
      Correct answer: Silicon dioxide

      Q2.
      In a chemical reaction, what are the substances called that start the reaction?

      Correct Answer: reactants

      Q3.
      True or false?: A physical change alters the chemical composition of the substance.

      True
      Correct answer: False

      Q4.
      Which of the following statements best describes a chemical change?

      Ice melting into water
      Water boiling into steam
      Correct answer: Paper burning into ash
      Sugar dissolving in water

      Q5.
      What is the term for a substance that does not dissolve in water?

      Soluble
      Correct answer: Insoluble
      Miscible
      Desirable
      Unchangeable

      Q6.
      Name this chemical: MgO

      magnesium oxygen
      Correct answer: magnesium oxide
      oxomagnesia
      oxymagnesium

      6 Questions

      Q1.
      What does the "+" symbol represent in a chemical equation?

      Plus
      Correct answer: And
      Or
      Equals

      Q2.
      In an oxidation reaction, what chemical substance does a reactant combine with?

      Correct Answer: oxygen

      Q3.
      What is produced in a decomposition reaction?

      A single new substance
      Correct answer: Two or more new substances
      An insoluble salt
      Oxygen

      Q4.
      In a chemical equation the signifies "changes into", indicating the transformation of reactants into products.

      Correct Answer: arrow

      Q5.
      A reaction that forms an insoluble salt when two solutions are mixed is called a reaction.

      Correct Answer: precipitation

      Q6.
      Which of the following are oxidation reactions?

      Correct answer: H₂ + O₂ → H₂O
      CaCO₃ → CaO + CO₂
      Correct answer: 2Mg + O₂ → 2MgO
      NaCl + AgNO₃ → AgCl + NaNO₃

      To help you plan your 10 chemistry lesson on: Three types of chemical reaction, download all teaching resources for free and adapt to suit your pupils' needs...