What Does Sunlight, Stars, and Florescent Light All Have in Common?

Rosia Sowell

Instructor Linda Hanson

Chemistry 104L

Fall 2016

Module 5 Activity

Introduction:

What does sunlight, stars, and florescent light all have in common? They are each a form of white light. White light can be defined as the complete combination or mixture of the colors or wavelengths of the visible spectrum. In other words, when all the colors come together, they create a cohesive appearance of only one color, which is white. Using a CD/DVD, white light can be explored and viewed, so to speak, in a different light. Why a CD/DVD?  Well, CD/DVDs have grooves in them that record the wavelengths of the music and/or movie it holds. When introduced to light, those grooves reflect different colors at different angles. This experiment probes into the visible region of the spectrum, for the purpose of separating light into different colors.

Materials:

Procedure:

Making the Spectometer

1. Begin with an empty cereal box.

2. With the box cutter, make a slit on the side of the box, about 30 degrees from the bottom of the box.

3. On the opposite side of the box, tape a strip of aluminum foil to the box and make a small horizontal slit (about 1 inch in length) into the box, over the aluminum foil.

4. Next cut an opening into the top of the box, above the first cut that was made, this will act as a window to observe the activity of the experiment.

5. Then, place the CD/DVD, shiny side up into the first cut that was made.  

Experiment:

1. Fill the cylinder with 15 ml of tap water.

2. Using a pipette, place 5 ml of water into each of the three test tubes and space the test tubes out within the cuvette.

3. Into one of the three test tubes drop 10 drops of red food color and into another of the three test tubes drop 5 drops of red food color. (tube #1, 5ml plain water, tube #2 10drops of color/5ml water, tube #3 5drops of color/5ml water).

4. Turn on the lamp (shade removed) with the 40w soft white light.