Tell students to shine white light through the prism in order to see the visible spectrum they have just modeled. This demonstration works best if a flashlight is shone on the prism in a darkened room. If this situation is not possible, sunlight in a regularly lit room will also work, but the colors will be less vivid. Students are to record the colors they see, from top to bottom, in the space provided on their data sheet. Discuss how wavelength contributes to the amount of refraction, or the deflection of light waves as they pass from one substance to another.
Red light has the longest wavelength in the visible spectrum and therefore reflects the least.
It is found at the top of the visible spectrum. Violet light has the shortest wavelength in the visible spectrum and therefore reflects the most. It is seen at the bottom of the spectrum. Discuss how the colors we see are actually light that is reflected by objects. For example, a red apple absorbs all colors of light except red.