When students are learning about the formation of rainbows and light refraction, students can create an indoor rainbow. The project requires a small mirror, a light and a cup or bowl of water, making it an ideal project for classroom spaces. The mirror is placed in the bottom of the cup or bowl of water. The light is held over the mirror and water, making a rainbow appear on the wall. In this experiment, children learn about the way light reflects to form rainbows.
As an activity to show students about different densities without involving potentially messy chemicals, teachers can use the rice pop-up ball experiment. Students are given a jar filled partially with uncooked rice, around 75 percent. The students then bury a small rubber ball in the rice. The jar is put on the table and the students give the table a few shakes. The ball rises to the top of the jar, showing that it is less dense and thus "floats" on top of the rice.
For an interesting and enjoyable activity that helps students learn about chemical reactions, a baking-soda-bubble project is ideal. It requires ¼ cup of baking soda, 1 cup of vinegar, bubbles liquid with a bubble wand and a large clear container. The baking soda is added to the container and the vinegar is added on top, which starts a fizzing reaction. Blow bubbles so the bubbles are on top of the bubbling mixture and the bubbles should float on top. Students see an illustration of chemical reactions as well as material density.
The string telephone experiment is related to the way sound travels. It requires two paper cups, a three- to four-foot-long string, a pencil and two paperclips. Poke a small hole at the bottom of the cups with the pencil. Tie one paperclip to the end of the string and put it inside one of the cups. Thread the non-paper-clip end of the string through the cup on the inside and through the outside of the other cup. Tie the second paperclip to the string on the inside of the second cup and adjust the string so it can pull tight. One student should hold the cup to his ear while the other student talks into the cup. The voice should alter, but still be heard.