• Quick retrieval from earlier learning (The reactivity series and displacement). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Reactivity series (most reactive first): potassium, sodium, calcium, magnesium, aluminium (aluminum), zinc, iron, copper, silver, gold. If zinc is added to a solution of aluminium (aluminum) sulfate, will a displacement reaction happen? (yes / no) → noPrompt: A more reactive metal displaces a less reactive metal from its compound.
2. Iron is extracted from iron oxide by heating it with carbon. Why does this work? (Carbon is more reactive than iron, so it removes the oxygen / Carbon is a metal / Iron is more reactive than carbon / Heat alone splits iron oxide) → Carbon is more reactive than iron, so it removes the oxygenPrompt: This is a type of displacement (reduction).
3. Reactivity series (most reactive first): potassium, sodium, calcium, magnesium, aluminium (aluminum), zinc, iron, copper, silver, gold. If iron is added to a solution of magnesium sulfate, will a displacement reaction happen? (yes / no) → noPrompt: A more reactive metal displaces a less reactive metal from its compound.

• Drop an antacid tablet in water (or show a clip) and ask whether a new substance is being made.
• Share the objective: How metals are extracted from their ores. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: How is iron usually obtained?
• Step 1: Metals less reactive than carbon can be extracted by heating their oxides with carbon.
• Step 2: So the answer is: reduction with carbon
• Answer: reduction with carbon
• 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. How is tin usually obtained? (electrolysis / reduction with carbon / found as the native metal) → reduction with carbonPrompt: Compare the metal's position in the reactivity series with carbon.
2. Why is recycling aluminium cans so worthwhile? (Aluminium cannot be extracted from ore / It uses about 5 % of the energy needed to extract new aluminium / Recycling makes aluminium heavier / New aluminium is radioactive) → It uses about 5 % of the energy needed to extract new aluminiumPrompt: Extracting aluminium uses electrolysis.

• 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. Extracting metals: which statement is NOT true? (Life cycle assessments compare the environmental impact of products. / Aluminium can be extracted by heating its oxide with carbon. / Gold is found uncombined because it is very unreactive. / Carbon can reduce zinc oxide to zinc.) → Aluminium can be extracted by heating its oxide with carbon.Prompt: Is aluminium above or below carbon in reactivity?
2. Bioleaching uses bacteria to extract copper. What is a drawback? (It needs huge amounts of electricity / It is slow and can produce toxic leachate / It releases large amounts of carbon monoxide / It only works on gold) → It is slow and can produce toxic leachatePrompt: Bacteria work slowly.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-10.