Models of the Hydrogen Atom
Learning objectives:
• TSW connect the importance of inference from experimental data.
• TSW explain the concept of energy absorption and energy emission.
• TSW identify the significance of only specific wavelengths of light being absorbed or emitted.
1. Open the "Models of the Hydrogen Atom" simulation at http://phet.colorado.edu/en/simulation/hydrogen-atom
2. Be sure to turn the light beam "on."
3. Before beginning the simulation answer the following questions about hydrogen:
# of protons:
# of electrons:
Electron configuration:
Outer shell:
4. Using resources from the internet, define a photon. Is the photon a particle or a wave?
5. What determines the color of a photon?
6. Making sure the "experiment" is hi-lighted white, observe what is happening while photons are being sent through a hydrogen atom. Write your observations below:
7. When determining how an atom works, scientists witnessed something similar to what you are witnessing now. They then deduced how the atom must be organized. What do you think is making the photons deflect? Is every color deflected?
8. Change the Light control from "White" to "Monochromatic". Are photons still being deflected?
9. Click the "show spectrometer" box.
10. Change the colors of the photons by moving the handle up and down the spectrum. Record your observations in the chart below:
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Color
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Observation
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UV
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Purple
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Green
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11. Click the "Show absorption wavelengths" box.
12. What is the spectrometer box keeping track of?
13. Now that you've theorized about what is happening to the photons of energy, hi-light the prediction button white and observe other scientist's theories about the atom.
** Be sure to return your wavelength to 97 nm and alternate between it and white light.**
Flip back and forth between "experiment" and "predictions" to compare the two.
14. Complete the chart below by comparing the 6 models with the experiment (what is really happening) and explain why the model does/does not explain the experimental observations.
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Atomic Model
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Observations
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How does it support or not support the experiment?
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Billiard Ball
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** notice the spectrometer**
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Plum Pudding
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Classical Solar System
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Bohr
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De Broglie
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Schrodinger
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15. With the Bohr's model selected, click the "Show electron energy level diagram."
16. Using the Electron Energy Level Diagram and the spectrometer, describe what is happening to hydrogen's one electron.
17. In the help menu, click on transitions. Enter the first 5 wavelengths into the wavelength box and observe what happens to the electron. Does this support your statement in number 16? If not, readjust your statement to explain the new behavior of the electron.
18. Now enter wavelengths that are not listed. What do you observe? Does this support your statement in number 16? If not, readjust your statement to explain the new behavior of the electron.