This activity has students play the roles of various atoms and molecules to help them better understand the formation and destruction of ozone in the stratosphere. At the conclusion of this activity students will understand how ozone is formed in the earth’s stratosphere and will be able to explain the importance of stratospheric ozone. They also will be able to explain how ozone is destroyed in the stratosphere, understand that some chemicals can speed up the breakdown of ozone in the atmosphere, and explain why chlorofluorocarbons (CFCs) are destructive to the ozone layer. The page contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.