Page 5 - COMPOSITION AND PROPERTIES OF AIR

2. Air has mass.

 Air also has mass. However, we do not feel the mass of air.
 For example, when we tie a balloon on each end of the stick with the
help of strings. On pricking one balloon, the balloon bursts, releasing
the air. The end of the stick that holds the punctured balloon goes up
and the other end that holds the blown balloon comes down. This is
because the blown balloon contains air. This shows that air has mass,

that makes the blown balloon heavier than the punctured balloon.

3. Air exerts pressure.

 Air also exerts pressure. However, this pressure acts in all directions.
 For example, if we take a juice can and make a hole in the lid of a juice
can, we can see when we first pour the juice in a glass; it comes out very
slowly from the hole. When we make a second hole in the lid, air enters

the can from there and pushes the juice out of the can. Thus, the juice
comes out faster. This shows that air exerts pressure.