Print off the student's worksheet and photocopy one for each student . Ask the students to carry out the activity from the worksheet then go over their results at the end of the class. From the end of the tank, the light beam appears to be yellow-orange. From the side of the tank, the light looks bluish-white. When light collides with gases in the earth's atmosphere the light is scattered.
Blue light has a short wavelength and scatters more thank red light.
The light reaching our eyes from the sky is blue. At sunrise and sunset, sunlight passes through far more air before reaching us. Extension activity Move your eyes along the container. Try the activity using a piece of cardboard with a hole punched in it to produce a sharper light beam. Investigate the effect of placing a polarising film in the light path.