Activity: Parts of an Atom
Purpose: To simulate the use of alpha particles to investigate how atoms are put together.
Materials: regular-size aluminum pie pan, 4 glass marbles, 4 small "super balls," 1 large "super ball," grooved ruler, flat piece of cardboard
Procedures:
Note - If you have trouble following directions, see the photos on page
119 in your textbook.
| 1. Gently press the four glass marbles into the pie pan so that they
make small indentations near the center of the pan.
2. Roll the large super ball down the grooved ruler. Try to hit the marbles. 3. Notice what happens to the large super ball. 4. When does the large super ball change its path? ______________ Does the large super ball ever bounce back? __________________ |
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5. Place the ruler at different slopes (steepnesses), and repeat steps 2 and 3. What are the differences in your observations from #4?
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6. Now put small super balls into the indentations in the pie pan, and roll a glass marble down the ruler. Repeat steps 2, 3, and 5. Compare and contrast the results with the results you observed with the glass marbles.
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7. Why did you get different results with the small super balls than with the glass marbles?
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8. What effect did the slope of the ruler have on the way the rolling
ball or marble behaved? (Explain in terms of slope and speed of roll).
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9. Which has a greater effect on the way the rolling ball acts after a collision, the mass of the rolling ball or the mass of the ball in the indentation?
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10. How is this activity like Ernest Rutherford's experiment?
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11. How is this activity different from Rutherford's experiment?
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12. How would your observations change if all the marbles and balls were positively charged?
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13. Label the lettered portions of the diagram below, which represents Rutherford's experiment.
