1. Do Now! Can you continue with the questions you were doing last lesson (Expansion)?

2. Today’s lesson Describe qualitatively the thermal expansion of solids, liquids and gases Identify and explain some of the everyday applications and consequences of thermal expansion Describe qualitatively the effect of a change of temperature on the volume of a gas at constant pressure

3. Gather round!

4. Expansion Many substances expand when heated When heated, the particles (atoms or molecules) in a substance vibrate more This means they need more space So the substance expands Heat

5. Important note! The particles in a substance do not expand themselves! Heat Particles are the same size

6. Contraction The opposite happens when most substances are cooled The particles vibrate less They need less room The substance contracts Cools

7. Solids The expansion of solids is small but strong! Like me!

8. Expansion in solids This means that we sometimes have to take into account expansion

9. Expansion in solids This means that we sometimes have to take into account expansion

10. Contraction can also be a problem

11. Liquids Most liquids expand when heated

12. Gases Gases expand a lot when heated! http://www.youtube.com/watc h?v=A843PL6Yejs&feature=re latedhttp://www.youtube.com/watc h?v=A843PL6Yejs&feature=re lated http://www.youtube.com/watc h?v=ZgTTUuJZAFs&feature= related

13. Let’s try an expanding worksheet!

14. Temperature and volume of a gas at constant pressure http://phet.colorado.edu/en/simulation/gas- properties

15. Temperature and volume of a gas at constant pressure When a gas is heated (at constant pressure), the gas expands. Can you copy this please?

16. HOMEWORK Due Thursday 22nd March Finish Expansion, Evaporation and Gas pressure sheets