• Quick retrieval from earlier learning (Reactants, products and word equations). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Complete the word equation: magnesium + oxygen → ___ (copper oxide / carbon dioxide / magnesium oxide / magnesium chloride) → magnesium oxidePrompt: A metal reacting with oxygen makes a metal oxide.
2. Why does a candle under a glass jar go out? (The wax turns into water / The jar gets too heavy / Glass puts out flames / The oxygen inside is used up) → The oxygen inside is used upPrompt: What does burning use from the air?
3. Word equations: which statement is NOT true? (Combustion is a reaction with oxygen. / The arrow in a word equation means "equals". / Reactants are written on the left of the arrow. / Thermal decomposition breaks a substance down using heat.) → The arrow in a word equation means "equals".Prompt: Which side of the arrow is which?

• Drop an antacid tablet in water (or show a clip) and ask whether a new substance is being made.
• Share the objective: Combustion, oxidation and the fire triangle. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Complete the word equation: calcium + oxygen → ?
• Step 1: metal + oxygen → metal oxide
• Step 2: So the answer is: calcium oxide
• Answer: calcium oxide
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. Complete the word equation: magnesium + oxygen → ? → magnesium oxidePrompt: When a metal reacts with oxygen it forms an oxide.
2. Why is a gas boiler with a poor air supply dangerous? (It produces too much oxygen / It makes the water too pure / Incomplete combustion produces toxic carbon monoxide / It stops producing heat completely) → Incomplete combustion produces toxic carbon monoxidePrompt: What forms when there is not enough oxygen?

• Students work on the student sheet. Circulate and check the first two answers of every student early.
• Students who finish: write a question of their own for a partner, with the answer.

The 8 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Combustion: which statement is NOT true? (Burning fossil fuels releases carbon dioxide. / Rusting is a slow oxidation reaction. / Hydrogen burns to make only water. / Combustion is an endothermic reaction.) → Combustion is an endothermic reaction.Prompt: Is energy taken in or given out when something burns?
2. Complete the word equation: sodium + oxygen → ? → sodium oxidePrompt: When a metal reacts with oxygen it forms an oxide.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-7.