• Quick retrieval from earlier learning (Evaluating experiments (research summaries)). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Experiment 1: Magnesium ribbon was added to hydrochloric acid at concentrations of 0.5, 1.0 and 2.0 mol/dm³ at 25 °C, and the gas volume after 1 minute was measured. Experiment 2: The 1.0 mol/dm³ acid was used at 15 °C, 25 °C and 35 °C. In Experiment 2, which variable was changed on purpose? (the colour of the magnesium / the acid concentration / the temperature / the volume of gas after 1 minute) → the temperaturePrompt: Look only at the description of Experiment 2.
2. Experiment 1: A student dropped the same ball from heights of 0.5 m, 1.0 m and 1.5 m onto a wooden floor and measured the bounce height. Experiment 2: The student dropped the same ball from 1.0 m onto wood, carpet and concrete. Which variable was kept constant in Experiment 2 but changed in Experiment 1? (the mass of the ball / the bounce height / the floor surface / the drop height) → the drop heightPrompt: What was tested in Experiment 1?
3. A study finds a result with only 3 samples. What is the best next step? (Repeat with a larger sample / Publish it as proof / Change the data / Use fewer samples) → Repeat with a larger samplePrompt: Small samples can give misleading results.

• Show a simple experiment with one thing changed and ask what makes it a fair test.
• Share the objective: Comparing scientific explanations (conflicting viewpoints). Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Two students explain why a ball rolling on a flat floor eventually stops. Student 1: Objects naturally slow down and stop when nothing keeps pushing them. Student 2: Friction and air resistance act against the motion; with no resistive forces, the ball would keep moving at a steady speed. Which student's view agrees with Newton's first law?
• Step 1: Newton's first law: an object keeps moving at constant velocity unless a resultant force acts.
• Step 2: So the answer is: Student 2
• Answer: Student 2
• 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. Peer review means… (the result can never be questioned / friends vote on the result / the scientist checks their own work only / other scientists check work before it is published) → other scientists check work before it is publishedPrompt: "Peers" are other experts in the same field.
2. Two students explain why a metal spoon in hot soup feels hotter than a wooden spoon in the same soup. Student 1: The metal spoon is at a higher temperature than the wooden spoon. Student 2: Both spoons reach a similar temperature at the end in the soup, but metal conducts thermal energy into your hand much faster, so it feels hotter. Which student's explanation depends on how fast energy is transferred? (Neither student / Student 1 / Student 2 / Both students) → Student 2Prompt: Read each viewpoint and underline its key claim.

• 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. Peer review means… (the scientist checks their own work only / friends vote on the result / the result can never be questioned / other scientists check work before it is published) → other scientists check work before it is publishedPrompt: "Peers" are other experts in the same field.
2. Two students explain why a metal spoon in hot soup feels hotter than a wooden spoon in the same soup. Student 1: The metal spoon is at a higher temperature than the wooden spoon. Student 2: Both spoons reach a similar temperature at the end in the soup, but metal conducts thermal energy into your hand much faster, so it feels hotter. A thermometer shows the tips of both spoons in the soup at the same temperature. This result supports… (Student 2 / Student 1 / both students equally / neither student) → Student 2Prompt: Read each viewpoint and underline its key claim.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-11.