• Quick retrieval from earlier learning (Physical and chemical changes). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Is this a physical or a chemical change: fireworks exploding? (physical change / chemical change) → chemical changePrompt: Is a new substance made?
2. A nail left outside turns orange-brown and flaky. What has happened? (The nail melted / Iron reacted with oxygen and water to make rust / The nail dissolved / Paint fell on it) → Iron reacted with oxygen and water to make rustPrompt: Rusting needs both air and water.
3. Physical and chemical changes: which statement is NOT true? (In a chemical reaction, atoms are rearranged to make new substances. / Dissolving is a physical change. / Melting is a chemical change. / Burning is a chemical change.) → Melting is a chemical change.Prompt: Does each change make a new substance?

• Drop an antacid tablet in water (or show a clip) and ask whether a new substance is being made.
• Share the objective: Reactants, products and word equations. 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: calcium + oxygen → calcium 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: iron + oxygen → ___ (iron carbonate / carbon dioxide / calcium oxide / iron oxide) → iron 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?

• 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. Complete the word equation: magnesium + oxygen → ___ (carbon dioxide / calcium oxide / magnesium oxide / magnesium carbonate) → magnesium oxidePrompt: A metal reacting with oxygen makes a metal oxide.
2. Word equations: which statement is NOT true? (Incomplete combustion can produce carbon monoxide, a poisonous gas. / Products are the substances you start with. / Combustion is a reaction with oxygen. / Reactants are written on the left of the arrow.) → Products are the substances you start with.Prompt: Which side of the arrow is which?

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