• Quick retrieval from earlier learning (Sound comes from vibrations; The particle model). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Rice grains on a drum jump when the drum is hit. What does this show? (The drum is magnetic / The rice is alive / The drum skin is vibrating / Sound is made of rice) → The drum skin is vibratingPrompt: What makes the rice move?
2. Which state is described: particles touching but able to slide past each other? (solid / liquid / gas) → liquidPrompt: How close are the particles, and how do they move?
3. Sound: which statement is true? (Loud sounds do not involve vibrations. / Sound travels through space between planets. / Sounds get fainter as you move further from the source. / Sound cannot travel through water.) → Sounds get fainter as you move further from the source.Prompt: Can sound travel where there is nothing at all?

• Ask the class to make a wave with a rope or slinky and describe what moves and what doesn't.
• Share the objective: How sound travels through solids, liquids and gases. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Why does sound travel faster in steel than in air?
• Step 1: Sound travels at about 340 m/s in air, 1500 m/s in water and over 5000 m/s in steel.
• Step 2: So the answer is: Particles in solids are close together and strongly linked, so vibrations pass on quickly
• Answer: Particles in solids are close together and strongly linked, so vibrations pass on quickly
• 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. Why does sound travel faster in steel than in air? (Particles in solids are close together and strongly linked, so vibrations pass on quickly / Sound is magnetic / Air has no particles / Steel is shiny) → Particles in solids are close together and strongly linked, so vibrations pass on quicklyPrompt: Think about how close particles are.
2. Sound travels at about 340 m/s in air. How far does it travel in 3 s, in m? → 1020 mPrompt: distance = speed × time

• 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. In which direction do air particles vibrate when a sound wave passes? (up and down, at right angles to the wave / backwards and forwards, parallel to the direction the sound travels / they do not move / in circles) → backwards and forwards, parallel to the direction the sound travelsPrompt: Sound is a longitudinal wave.
2. Sound travels at about 340 m/s in air. How far does it travel in 4 s, in m? → 1360 mPrompt: distance = speed × time

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