Activity Description

The students begin this activity by observing the simulated emmission spectrum of hydrogen. The students are then presented with the following statement made by a fictitious student, “In the absorption spectrum for hydrogen, the hydrogen emits a continuous spectrum except at the wavelengths corresponding to the lines in the hydrogen emission spectrum.” The students then have to answer the question what if anything is wrong with the statement.

Target Conceptual Difficulty

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

PowerPoint

What if anything is wrong task - Light Emission (TurningPoint)
What if anything is wrong task - Light Emission (iClicker)

Simulation

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

Click on the button marked Simulations. On the page that appears click link for Emission next to the Gas Lamps label. Click on the hydorgen lamp and drag it so that it falls into the sockets to show the emission spectra of hydrogen.

Presentation Notes

Once the simulation is set up, I first show students the emission spectra of hydrogen. I then have them click on what the best description (I give them three choices) of the spectrum. Next I pose the WWT task to them. Once they have clicked following small group discussion, I resolve the question by showing them the spectrum again.

Student Results

This task proved to be quite challenging for the students. The incorrect "student" statement was quite attractive and following small group discussion, over half of the students went with the choice that the "student" statement was correct.

Individual Respoinse

1.) What if anything is wrong with the student's statement?
Responses
(percent) (count)
The statement is correct 40.91% 9
The light is emitted by a source different than the hydrogen. The missing lines have nothing to do with hydrogen
4.55% 1
The hydrogen emits at all frequencies just a smaller amount for the dark lines
9.09% 2
Hydrogen absorbs light from another source, and reemits in all directions reducing the brightness
45.45% 10
Totals 100% 22

Respose follwoing small group discussion

2.) What if anything is wrong with the student's statement?
Responses
(percent) (count)
The statement is correct 54.55% 12
The light is emitted by a source different than the hydrogen. The missing lines have nothing to do with hydrogen
4.55% 1
The hydrogen emits at all frequencies just a smaller amount for the dark lines
0% 0
Hydrogen absorbs light from another source, and reemits in all directions reducing the brightness
40.91% 9
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