Thursday, February 4, 2010

Does Air Weigh Anything?

This easy activity answers the question, "Does air weigh anything?" You may be surprised at the answer!


2 Balloons of equal size
(NOTE: If you don't own a balance, the child can make his/her own. Take a ruler that has 3 holes in it. Put one paper clip in each of the 3 holes. Hang the ruler/balance by the middle paper clip on a rod.)

1. Ask the child, “Do you think air has mass (weight)?
2. Hang one balloon on one end of the ruler balance by attaching to the paper clip.
3. Blow up the second balloon.
4. Attach the second balloon to the other end of the ruler balance.
5. Compare weights.

The fact that air has mass (weight) is an important concept for children to grasp. Air is matter. Matter must satisfy two conditions: it must take up space, and it must have mass (weight). This activity vividly shows that yes, air has mass, because the balloon which was blown up will pull its end of the ruler down. When they are older, they will learn how to calculate, using a periodic table, the mass of different gases. It’s easy!