1. P1a 1.3 Conduction

2. Lesson Objectives To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

3. Task Draw the particle arrangement for a solid, liquid and gas. Each diagram should have a maximum on 9 particles. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

4. solid liquid gas Particles that are very close together can transfer heat energy as they vibrate. This type of heat transfer is called conduction. What type of solids are the best conductors? Conduction is the method of heat transfer in solids but not liquids and gases. Why? Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

5. Conduction in Metals Aim: Testing conduction of heat in Metals. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

6. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

7. heat Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour What happens when you heat a metal?

8. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour Firstly – What is a metal? Non-Metals Metals

9. Sodium (Na) Is a solid. Na 23 Sodium 11 Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

10. A Closer Look Inside Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

11. Element structure Na 23 Sodium 11 Atomic Number – the number of protons and electrons. (11p and 11e) Mass Number – the number of protons and neutrons. (11p and 12n) Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

12. Element structure Na 23 Sodium 11 pnpn The maximum number of electrons in each shell is 2, 8 and 8. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

13. Element structure HydrogenHelium Lithium CarbonNitrogen Oxygen Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

14. Metals are good conductors of heat. The outer electrons of metal atoms are not attached to any particular atom. They are free to move between the atoms – therefore are called FREE ELECTRONS When a metal is heated, the ions vibrate more and the free electrons gain kinetic energy. heat This means that the free electrons move (diffuse) faster and transfer the energy through the metal through collisions with other free electrons and ions in the cooler region. This makes heat transfer in metals very efficient. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

15. What about non-conductors? These are called Insulators. Air is one of the best Insulators (woolly jumpers) Insulators have no FREE ELECTRONS. They do not conduct heat as well as metals. Instead the atoms hold the electrons firmly in place. Instead thermal energy is transferred through atom vibration instead (less effective). Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour heat

16. Conclusions Metals conduct heat better than non metals. Copper is a better conductor than steel. Wood conducts heat better than glass. The transfer of heat is faster when the temperature difference is greater. Remember: We know that metals are good conductors – think of a barbeque, you don’t touch the metal when it is hot! Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

17. Investigation Use different materials to insulate identical beakers of hot water. Control variables – amount of water, starting temperature, type of thermometer, same time period. Try to explain what is happening in terms of type of heat transfer and particle theory. Keywords: To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour

18. Are you now able to…. I still feel unsure. I need some more help to understand. I feel ok. I need to do some more work to check my understanding. I am happy and feel I understand and can explain the main points. To state that metals are good conductors of thermal energy. To list poor conductors or insulators. To explain why metals are good conductors of thermal energy in terms of electron behaviour