This activity is a counterpart to the reading The Two Faces of Ozone. It is meant to reinforce the concept that while ozone is essential in the stratosphere, it is undesirable at ground level. This is not a hard activity, and it allows the students to experience chemistry as it operates in the real world of their immediate surroundings, and to see it impacting their daily lives.

Notes

This activity is best carried out in the warmer mnths of the year, when ground-level ozone concentration tends to be at its highest. During the winter months any color change may be hard to observe.

When carrying out the section of the activity "The Big Picture," it will help to familiarize yourself with a map of the area where your students live. Find out where major sources of ozone pollution (such as factories or expressways) might be in their neighborhoods, and mark them on them map you will be using to plot their ozone readings. This will help students determine why some places might show higher ozone levels than others.

Safety

This activity does not involve dangerous materials, but make sure students wear eye protection while carrying out the activity, and that they follow the General Safety Guidelines.

AIRNOW — contains information on ground-level ozone, including ozone level maps for many states, from the U.S. Environmental Protection Agency, Office of Air Quality Planning & Standards.