Rutherford experiment

Project title: Rutherford experiment

This virtual laboratory is intended for use in chemistry classes on the following topics:

  • 10th grade. Chapter I. Atomic structure.

Goals:

  • To study the Thomson and Rutherford atom models, their main characteristics and differences.
  • To understand Rutherford’s experiment and its significance for the development of ideas about the atomic structure.
  • Conduct a virtual experiment simulating Rutherford’s experiment and analyze its results.

Practical part

Replicate Rutherford’s experiment to understand the structure of an atom.

  1. To begin, launch the PhET simulation. You will be presented with two modes: Rutherford atom and Plum pudding atom. Let’s first explore the possible outcome of the experiment using Thomson’s model. Select the Plum pudding atom mode.

2. On the screen, you can see a thin gold foil, an enlarged image of its atom as a “plum pudding” with electrons like “raisins”. In the top right corner of the screen is the “Legend” section, which shows the components of the atom. In the “Alpha particle” section, you can adjust the intensity of the alpha particle bombardment by moving the slider to the right or left.

3.Initiate alpha particle bombardment. Set the intensity to maximum. Enable the “Traces” option to track particle trajectories. Analyze the particle deflections. Repeat the bombardment with minimum intensity. Observe any particle scattering. What about the case when particle bombardment is at its lowest intensity?

4. Switch to the “Rutherford atom” mode, which represents the planetary model of an atom. In this model, the massive, positively charged nucleus is located at the center, surrounded by electron energy level orbitals.

5. The simulation allows observation of the experiment at both the multi-atom and nucleus levels. In the “Atom” section, you can modify the nuclear composition by adjusting the number of protons and neutrons.

6. Set the number of protons and neutrons to their minimum values. Bombard the atoms with alpha particles.

7. Repeat the previous step with the maximum number of protons and neutrons.

8. Questions:

  • What are the key differences you observed between Thomson’s and Rutherford’s models during the experiment?
  • How does the intensity of alpha particle bombardment affect the outcome of the experiment?
  • How does the number of protons and neutrons in the nucleus influence the alpha particle deflection angle?

Conclusion

In this activity, students explored the Thomson and Rutherford models of the atom, followed by a virtual experiment that simulated Rutherford’s experiment.