Activity Description

The students are first shown a simulated absorption spectrum of hydrogen. They are then shown the emission spectrum and asked to predict and explain their prediction for the absorption spectrum of helium.

Target Conceptual Difficulty

Inability of students to distinguish betwen an emission and an absorption spetrum.

PowerPoint

Predict and Explain Task - Absorption Spectra

Simulation

http://phys.educ.ksu.edu/

Click on the button marked Simulations. In this activity you will change back and forth between the Gas Lamps Emission and Absorption Spectra simulations.

Presentation Notes

Once the simulation is set up, I first show students the emission spectra of hydrogen. Once I have reviewed the hydrogen spectrum, I then switch to the absorption spectrum simulaiton and show them the absorption spectra orf hydrogen. I then switch back to the emission spectra simulation and show them helium. I then ask them to predict the absorption spectra of helium. The question is resolved by showing the absorption spectrum of helium.

Student Results

The difficulties the students had with Activity 20 nicely set up this activity. Almost 80% of the students predicted the correct answer, and so no follow up answers were collected following small group discussion.

1.) Helium has the following emission spectrum. Predict which of the following is an absorption spectrum for He?

Responses(percent) (count)
Picture Choice 1 77.27% 17
Picture Choice 2 9.09% 2
Picture Choice 3 4.55% 1
Picture Choice 4 9.09% 2
Totals 100% 22

Pen and Paper Actvivities

Pen and Paper version of this activty

Follow up questions (only 1 tiper) from homework assignments, test reviews and test items