1. Physics Unit 1 Lesson A2: Part 1 Changing State Learning objectives: Recall that the energy required to change the state of an object depends on its mass; there is no change in temperature while changing state. Be able to perform calculations based on specific latent heat.

2. In the backs of your books draw the particle diagrams for a solid, a liquid and a gas. People will be asked to come up and draw their ideas on the board. Solid Liquid Gas

3. Do you agree? What are the important things to remember in each diagram? Solid Liquid Gas

4. Check yours against the correct versions. Draw the correct ones in the front of your books, with descriptions. Solid Regular Pattern Touching Not moving - Vibrating Liquid Random Pattern Touching Moving Randomly Gas Random Pattern Not touching – Far apart Moving Randomly - Fast

5. Which words would we put in each arrow? SolidGasLiquid Boiling Freezing Melting Condensing

6. Copy the correct diagram into your books. SolidGasLiquid Boiling Freezing Melting Condensing

7. Describe the what this graph is showing – talk about each section Time Temperature A B C D E

8. If this graph was for water, two very important temperatures could be added. What are they? Time Temperature ? ?

9. Were you right? What is important about 100 o C and 0 o C for water? Time Temperature 100 o C 0oC0oC

10. What is happening to the water in each section? Discuss with your partner Time Temperature A B C D E 100 o C 0oC0oC

11. Which phrase goes with each section? Time Temperature A B C D E 100 o C 0oC0oC Ice is warming up Ice is melting Liquid water is warming up Liquid water is Boiling Steam is warming up

12. Which phrase goes with each section? Time Temperature 100 o C 0oC0oC Ice is warming up Ice is melting Liquid water is warming up Liquid water is Boiling Steam is warming up

13. What happens to the temperature when the water is changing state? Time Temperature 100 o C 0oC0oC Ice is warming up Ice is melting Liquid water is warming up Liquid water is Boiling Steam is warming up

14. Draw this diagram very neatly in your books. Add more detail to the labels. Describe what is happening to the temperature in each section Time Temperature 100 o C 0oC0oC Ice is warming up Ice is melting Liquid water is warming up Liquid water is Boiling Steam is warming up

15. Recap Quiz – back of book 1.What is the unit for Temperature? 2.What is the unit for Energy? 3.What direction does heat flow? 4.What is the melting point of water? 5.Describe the particles in a Solid. 6.What do you call the change of state from gas to liquid? 7.What happens to the particles in a liquid as you heat it? 8.What happens to the temperature of a material when it changes state? 9..

16. Answers – write a sentence in the front of you book to answer each question correctly 1.What is the unit for Temperature? o C (your sentence could be “The unit for temperature is o C”) 2.What is the unit for Energy? Joules (J) 3.What direction does heat flow? From hot objects (which cool down) to cold ones (which heat up) 4.What is the melting and boiling points of water? Melting = 0 o C, Boiling = 100 o C 5.Describe the particles in a Solid. Touching, in a regular pattern, vibrating, not moving around 6.What do you call the change of state from gas to liquid? Condensing 7.What happens to the particles in a liquid as you heat it? The particles move around faster. 8.What happens to the temperature of a material when it changes state? The temperature stays the same when it changes state.