Write the numbers one through five on the labels.
Then attach a label to the top of each jar lid.
Place the jar lids on the cardboard. Carefully trace around the jar lids.
Then number these circles to match the labels on the lids.
Take the lids and cardboard outside. Place them flat in an open area.
(Note: Rain will spoil the results, so remind students to bring the
experiment inside if the weather turns inclement.)
At the end of the first day, have the children remove
one lid, starting with number one. Repeat this procedure for the
next five days, taking away one lid each day. Have students compare
the circles as they remove the lids. What observations can they make
as the days go by?
At the end of the fifth day, take away the last lid and look
at the circles. If the air is dirty, the circles covered by the low-numbered
lids will have more specks of dirt than the others. Have the
children use magnifying glasses to "count" the dirt specks.
Results and Discussion
Discuss results of experiment. Ask the students,
"Is our air clean or is it dirty?"
