Difference between revisions of "5-SLG-3"
Mrsaunders (Talk | contribs) (→Main Body of Lesson) |
Mrsaunders (Talk | contribs) (→Main Body of Lesson) |
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Demo Brownian motion (microscope) and here's an [http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/brownian/brownian.html animation] which shows what's going on. | Demo Brownian motion (microscope) and here's an [http://galileo.phys.virginia.edu/classes/109N/more_stuff/Applets/brownian/brownian.html animation] which shows what's going on. | ||
==Main Body of Lesson== | ==Main Body of Lesson== | ||
| + | Use the mechanical model for Brownian motion model gas particle behaviour: Piston moves up due to increase in pressure of gas caused by increase in temp. Pressure caused by molecules hitting the sides of the container, changing momentum and exerting a force on the side. | ||
| + | 1. Faster molecule – bigger force. Press = F/A so bigger Pressure. | ||
| + | 2. Faster molecules leads to more frequent collisions with sides – higher pressure. | ||
| + | Try to avoid shouting over the model (it's quite loud). Stop it periodically and discuss the changes that occur as you change the speed of the piston. There is a worksheet in the shared folder (Gas molecules and pressure) exploring these ideas. | ||
Another approach here is to use role play so that the pupils model what the particles are doing in solids, liquids and gases before moving onto Brownian motion (see Brownian motion role play in shared). | Another approach here is to use role play so that the pupils model what the particles are doing in solids, liquids and gases before moving onto Brownian motion (see Brownian motion role play in shared). | ||
Revision as of 09:35, 4 September 2012
Contents
Outcomes
- Pupils can describe Brownian motion
- Pupils can convert °C and K
Specification References
- 5.9 understand the significance of Brownian motion, as supporting evidence for particle theory
- 5.10 understand that molecules in a gas have a random motion and that they exert a force and hence a pressure on the walls of the container
- 5.11 understand why there is an absolute zero of temperature which is –273°C
- 5.12 describe the Kelvin scale of temperature and be able to convert between the Kelvin and Celsius scales
Starter
Demo Brownian motion (microscope) and here's an animation which shows what's going on.
Main Body of Lesson
Use the mechanical model for Brownian motion model gas particle behaviour: Piston moves up due to increase in pressure of gas caused by increase in temp. Pressure caused by molecules hitting the sides of the container, changing momentum and exerting a force on the side. 1. Faster molecule – bigger force. Press = F/A so bigger Pressure. 2. Faster molecules leads to more frequent collisions with sides – higher pressure. Try to avoid shouting over the model (it's quite loud). Stop it periodically and discuss the changes that occur as you change the speed of the piston. There is a worksheet in the shared folder (Gas molecules and pressure) exploring these ideas.
Another approach here is to use role play so that the pupils model what the particles are doing in solids, liquids and gases before moving onto Brownian motion (see Brownian motion role play in shared).
