1. The big question: What happens inside metals to allow electricity to flow? Why are we learning this?

2. Homework: p82, q4 Due: Thurs Mark what you’ve done in purple Please then leave for me to look at too, I won’t mind if you got it all wrong!

3. Learning Objective: To analyse current in metals The big question: What happens inside metals to allow electricity to flow? A – Predict the value of the boltzmann constant B – Criticize rms calculations C – Calculate rms, mass, and KE D – Summarize metallic bonding

4. Metallic Bonding Pick 1-2 roles: WORD COUNTER PRESENTER WRITER TIMER

5. You will prepare either a…. REPORT // POSTER // NEWSCAST On stealing metal and why metal is such a precious thing (D) How are metals bonded (D) Why do metals allow electricity to flow (C) What is RMS velocity? (C) How can you use energy of a metal to calculate RMS? (B) Why would RMS calculations be slightly incorrect

6. Delocalized means.. Kept in placeAble to move NeitherBoth

7. If total energy of a metal is 400J, r.m.s. velocity of one 9.1x10 -31 kg electron is… 800 x 9.1x10 -31 800 ÷ 9.1x10 -31 9.1x10 -31 x 800 9.1x10 -31 ÷ 800

8. r.m.s. is not an exact calculation because it is an average Electrons don’t move Some energy is lost It is a square root

9. Learning Objective: To analyse current in metals The big question: What happens inside metals to allow electricity to flow? A – Predict the value of the boltzmann constant B – Criticize rms calculations C – Calculate rms, mass, and KE D – Summarize metallic bonding

10. (D) Describe metallic bonding (C) If total energy of a metal is 1200J, r.m.s. velocity of a 9.1x10 -31 kg electron = ? (B) If you looked at one electron in a metal as it conducted electricity, why wouldn’t you see it moving at r.m.s.? (give 2 reasons) (A) Thermal kinetic energy of a metal = kT, where T is Temperature in Kelvin and k is the “Boltzmann constant”. What is an approximate size for k? Show your working

11. SeaShared Electrons Metallic Attracted Divide MassSquare root Multiply SpeedDelocalised Atoms

12. Learning Objective: To analyse current in metals The big question: What happens inside metals to allow electricity to flow? A – Predict the value of the boltzmann constant B – Criticize rms calculations C – Calculate rms, mass, and KE D – Summarize metallic bonding