• 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. When you speak, what vibrates to make the sound? (your hair / your vocal cords in your throat / your teeth / your eyes) → your vocal cords in your throatPrompt: Put your fingers on your throat and hum.
2. Which state is described: particles with lots of empty space between them? (solid / liquid / gas) → gasPrompt: How close are the particles, and how do they move?
3. Sound: which statement is true? (Sound cannot travel through water. / Loud sounds do not involve vibrations. / Sound travels through space between planets. / Sounds are made by vibrations.) → Sounds are made by vibrations.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. An alarm clock rings inside a jar. As the air is pumped out, the ringing gets quieter. Why? (Sound needs particles to travel through, and there are fewer left / Air makes sound quieter / The clock stops ringing / Glass absorbs all sound) → Sound needs particles to travel through, and there are fewer leftPrompt: Can sound travel through a vacuum?
2. Sound travels at about 340 m/s in air. How far does it travel in 2 s, in m? → 680 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. Sound travels at about 5000 m/s in steel. How far does it travel in 3 s, in m? → 15000 mPrompt: distance = speed × time
2. How sound travels: which statement is NOT true? (Sound travels faster in water than in air. / Sound waves are longitudinal. / Whales can communicate over long distances underwater. / Sound travels faster than light.) → Sound travels faster than light.Prompt: Why do we see lightning before we hear thunder?

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