• 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 calcium is added to a solution of zinc sulfate, will a displacement reaction happen? (yes / no) → yesPrompt: A more reactive metal displaces a less reactive metal from its compound.
2. Why is gold found as the pure metal in the ground? (It is very unreactive / It is very reactive / It is a non-metal / It is magnetic) → It is very unreactivePrompt: Where is gold in the reactivity series?
3. Reactivity series (most reactive first): potassium, sodium, calcium, magnesium, aluminium (aluminum), zinc, iron, copper, silver, gold. If copper is added to a solution of zinc 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? (It uses about 5 % of the energy needed to extract new aluminium / Recycling makes aluminium heavier / Aluminium cannot be extracted from ore / 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 6 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. Bioleaching uses bacteria to extract copper. What is a drawback? (It only works on gold / It releases large amounts of carbon monoxide / It needs huge amounts of electricity / It is slow and can produce toxic leachate) → It is slow and can produce toxic leachatePrompt: Bacteria work slowly.
2. Extracting metals: which statement is NOT true? (Life cycle assessments compare the environmental impact of products. / An ore is a rock containing enough metal to make extraction worthwhile. / Metal ores will never run out. / Gold is found uncombined because it is very unreactive.) → Metal ores will never run out.Prompt: Is aluminium above or below carbon in reactivity?

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