Making a rainbow using a hose pipe is an easy and colorful experiment. Go into your garden on a sunny afternoon; late afternoon is best because the sun is lower in the sky. Turn on the hose pipe and adjust the nozzle so that it sprays fine droplets of water. Stand with your back to the sun with the water spray in front of you. Look through the water spray and you will see a rainbow effect. As the sunlight passes through the water droplets, the light gets refracted and splits into the seven colors of the spectrum.
At first glance, the blank side of compact disk appears to be a completely flat surface. But if you were to look at it through a microscope, you would see that it has thousands of grooves. Shine a flashlight onto the compact disk or let the sun shine on it. Move the disk around slightly until you see a rainbow effect. This is because the CD is made of metal and the white light reflecting back to your eyes has been refracted by the grooves and separates the white light into the seven colors of a rainbow.
Put a glass prism on a table. Turn on a flashlight and shine it through the prism. Adjust the angle of the flashlight until a rainbow effect appears in the prism. The light from the flashlight is getting refracted by the prism; it splits into seven colors. The colors you see in the prism are always the same way around; red is on top and violet is on the bottom, the same as a rainbow. Refracted light bends at different angles; the smallest refracted angle of light is red and the largest is violet.
Fill a glass jar or bowl with tap water. Place the bowl on a sunny window ledge, ensuring that about 1 inch of the bowl protrudes over the ledge. The sunlight needs to shine through the bowl. Use a strip of clear tape and stick a couple of sheets of white paper together. Place the sheets of paper on a chair and put the chair directly below where the edge of the bowl protrudes from the window ledge. The light shining through the water in the bowl gets refracted and splits into the seven colors of the rainbow, which shine directly onto the paper. You may need to move the chair a bit to get in the right position. You will get a smaller but more vivid rainbow the closer the paper is to the bowl.