Here's a splashy (and magical) way to introduce the earth science idea that living creatures are made of carbon, hydrogen, oxygen and nitrogen. Sitting on a table are a piece of colored paper and a bottomless paper cup. Four small pieces of tissue paper are dropped into a bottomless paper cup. One piece of tissue paper has the letter C = carbon. One piece of tissue paper has the letter H = hydrogen. One piece of paper has the letter and number O2 = oxygen. The last piece of tissue paper has an N = nitrogen on it. They are momentarily covered by a paper cup. When the cup is lifted away, the pieces of paper have transformed into a little tissue paper person. Easy to perform. Fun.