We have shown that we can "see" air. Now, we want to feel it. Of course, we have all been outside on a windy day. We felt the air then, but we didn't think about it as being "air" because it was "wind."

Swing your hands through the air quickly and describe what you feel. Next, hold a stiff sheet of cardboard and swing your hands again. You will feel the cardboard pushing against something. It is pushing against air.

Now fill a balloon with air and hold the neck closed with one hand. With the other hand, squeeze and knead the balloon and describe how the air inside the balloon pushes back. When the neck of the balloon is released, you can feel the air rush out.