Anglia Ruskin University Ruthford Scattering Stimulation Worksheet

Unit V: Rutherford Scattering(PhET Interactive Simulations)
Navigate to the Rutherford Scattering simulation. Click play on the small screen and it will automatically
open up to a full screen. You will need to take screen shots of your work as you make your way through
the simulation. You can do this by selecting the three vertical dots in the bottom right hand corner of the
simulation screen and then selecting “Screenshot.” A screenshot will be downloaded to your browser
which you can save to your computer.
Rutherford’s Gold Foil Experiment
Once the simulation opens, click on the Rutherford Atom (you will come back in Part 2 and open the Plum
Pudding Model).
Part 1: Rutherford Atom
Before beginning this exercise, be sure you have read in the text about Rutherford’s Gold Foil experiment.
This will help in your understanding of what is happening in this simulation (section 2.2, page 49).
Once ready & with the simulation open, review the legend in the upper right so you have an
understanding of what is being shown in this simulation.
1. Set the number of protons to 20 (lower right side of the screen).
2. Click on the blue button on the Alpha Particles gun (lower left side of the screen) to start firing
Alpha particles towards the gold foil.
3. Click on the Traces button (In the “Alpha Particles” box on the right side). What do you notice
about the paths of most of the alpha particles?
4. Increase the number of protons to 60. Does it change how the alpha particles move? If so, how?
5. Now, increase the number of protons to 100. How does this increase change how the alpha
particles move through the gold foil as compared to when you started? Why do you think this
change occurred?
6. Take a screenshot with the proton number set to 100 and include it below.
7. Repeat the above steps, but vary how many neutrons (change it to 40 as an example). Does this
change how the Alpha particles travel? Why or why not?
8. How are the situations in #6 and #7 different? Why do you think this is?
Part 2: Plum-Pudding Atom
Before beginning this exercise, be sure you have read in the text about Rutherford’s Gold Foil experiment.
This will help in your understanding of what is happening in this simulation (section 2.2, page 48).
1. Switch the simulation to the Plum-Pudding Atom (center of the page ~ under the pause/play
buttons).
2. Once the simulation opens, click on the trace button (in the box on the right titled “Alpha
Particles”).
3. Click on the blue button on the Alpha Particle gun to turn on the Alpha particles. What type of
path do the Alpha particles take? Take a screenshot and include below with your description.
4. How is this different than the Rutherford simulation?
Conclusion
1. Why do you think that our model of the atom changed after Rutherford’s experiment?
2. Why were the Alpha particles deflected by the nucleus and not attracted to it?