(use a diagram to help you explain) Lesson Starter WRITE IN SENTENCES Describe what happens to the particles when you: a) Heat a substance up b) Cool a substance down (use a diagram to help you explain)

What’s the matter? Lesson 8

Lesson 8 – Learning Intention Expansions and contractions

Aim of the experiment We know that particles move faster when we give them more energy (by heating them up) Does this make the material (being heated) change in any way?

Apparatus Goggles Bunsen burner Metal ball and ring (or clamp and T bar) Clamp stand

Method Use the clamp stand to hold the ring (or clamp) securely Check the ball fits through the ring (or the t-bar fits into the clamp) Light the Bunsen burner and turn it to the warmest flame CAREFULLY roast the ball (or T-bar) for 1 minute Now try and see if it still fits- BE CAREFUL Hold the metal under the cold tap for a few minutes Check to see if it fits Turn off the Bunsen and let everything cool down

Safety Roasting hot metal is very dangerous What safety precautions do we need to take?

What did you see? Why do you think this happened? Results What did you see? Why do you think this happened?

Conclusion When we heat the particles up, we gave them more energy so they moved further apart causing the material to get bigger This is called EXPANSION

Conclusion When we cooled the metal back down, the particles didn’t have as much energy so couldn’t spread out as much The material got smaller This is called CONTRACTION

Particles The particles themselves DO NOT CHANGE SIZE It is the space between them that gets bigger or smaller

Summary On the post it provided, write your name and a summary of what you have learned about contraction and expansion