When light is passed through a prism, the rays of light are refracted and dispersed, resulting in a spectrum. In this activity we will explore the use of prisms and the spectra produced by different light sources. The results of the experiments should be recorded for inclusion in a short written report.

• Assortment of prisms: glass, plastic, equilateral, right-angle
• 8 1/2" x 11" white cards and stands (to be used as projection screens)
• Assortment of light sources: sunlight, laser pointer, white-light flashlight, red LED flashlight, fluorescent light

You will be given a prism, a small projection screen and a light source. You will conduct a number of experiments, based on the "Discovery" questions below. Many of the questions require you to compare spectra produced with different types of light sources. In this case, you are encouraged to work with the students sitting next to you, as they will posses different light sources than you do. In addition, some questions require you to compare different prisms or use more than one prism. In this case, you should form a group with the students sitting near you and perform the experiments as a team.

Do keep notes on the results of the experiments, as this information will be included in a short written report, the exact specifications of which will be discussed and determined at the end of the activity session.

• Is a spectrum produced regardless of what angle the light enters the face of the prism?
• Is a spectrum produced regardless of which face of the prism the light enters?
• What is the result of passing the light through a face of the prism at a right angle?
• Is there a difference in the spectra produced by a glass prism and a plastic prism?
• Is there a difference in the spectra produced by an equilateral prism and a right angle prism?
• How does the spectrum produced by sunlight compare with that produced by a white flash light?
• How does the spectrum produced by a laser pointer compare with that produced by a white flash light?
• How does the spectrum produced by a red LED flashlight compare with those produced by a white flash light and a laser pointer?
• How does the spectrum produced by fluorescent light compare to all of the other light sources?
• What happens if you pass light through two prisms?
• Is it possible to recreate Newton's double-prism experiment with the materials you have?
• As you move the projection screen farther away from the prism, the image gets larger. Does anything else happen to the image?