Revision as of 16:22, 11 May 2008

Outcomes

• Student should be able to describe and compare the Plum Pudding model and the Rutherford model of the atom.
• Students should recall that like charges repel.
• Using the observations from the Geiger and Marsden’s experiment they should be able to make conclusions about the structure of the atom and how they support the Rutherford model.

Specification References

• 7.15 Describe the results of Geiger and Marsden’s experiments with gold foil and alpha particles
• 7.16 Describe Rutherford’s nuclear model of the atom and how it accounts for the results of Geiger and Marsden’s experiment and understand the factors (charge and speed) which affect the deflection of alpha particles by a nucleus.

Starter

• Have students read outloud, and in turn, the dialogue on Radioactivity

Main Body of Lesson

• Use the Rutherford model to simulate the experiment. Start with ‘dilute positive sphere’ and then add the nucleus after. This should be done undercover (in a box) Students should only observe the result.
• Teacher must state that the alpha particles are positively charged.
• Emphasise the observations as a class and then split them into groups and using the observations and conclusions sheet they could try to draw a conclusion on the structure of the atom.

Plenary

• Remove the box and review the conclusions made

Homework

• Write a dialogue between two people explaining the plum pudding and Rutherford models, the Geiger and Marsden’s Experiment and how their observations led to the new model of the atom.

Additional Information

Resources Required

• One Ramp
• Set of metal balls
• One Rutherford model and one ‘dilute positive charge’ drawn on a piece of paper with two boxes to go over top. Boxes must have slits along base to allow ball to travel through.

Textbook References

• Physics for You p.g. 94-95

Website References

• none

Skills Addressed

• Observation

Safety/Hazards

• none

Notes

• None