Experiment with the concept of bending light. Bending light is called "refraction." Affix a coin to the bottom of a bowl and slowly add water. Notice how the coin seems to get bigger as the water level reaches the top of the bowl. Put some pebbles in the bowl and try to touch them with a straw. Notice that the pebbles are not in the same spot as they appear to be.
Sir Isaac Newton performed classic experiments to discover what makes up white light. Using a prism, he discovered that white light was actually a blend of colors -- all of the colors of the rainbow. Use a prism and white paper to break light apart. Try the same thing with a glass of water sitting in strong sunlight on a white piece of paper. Both will break white light into a spectrum of colors. A computer simulation of Newton's famous experiment can be found at the University of Chicago website (microcosmos.uchicago.edu/microcosmos_new/newton/glassworks/) and is appropriate for older students.
Mirrors illustrate how light is reflected back from a surface. A convex or concave mirror will change the shape of the light rays and will also change the reflection shown in the shiny surface. Look into shiny spoons of various sizes. Look in the front and in the back. Notice how the reflection changes. Draw a shape and then put it in front of a mirror. Try to copy the shape by only looking in the mirror. Discuss why reflections are not exact copies of real things.
Encourage students to discover what happens to the shadow of an object when a light source is moved farther from it and closer to it. Provide groups of students with flashlights, white paper, pencils for tracing and a couple of common objects, such as small toy cars, paper cups or soup cans. Ask students to move the light source to various spots -- 1 foot away, 2 feet away, 6 inches away -- and to trace the shadow. Ask students to brainstorm about the reason for the changes in shadow shapes.