Experiment 7:
Where can we find air?
This
experiment will demonstrate that air is all around. It occupies every free space,
however small.
Introduction:
Materials
required:
A
glass
Ping pong ball
Piece of kitchen paper
Transparent bowl / basin containing water (deeper than the glass)
Experiment:
What
happens?
Crush
the paper into a ball and place in the bottom of the glass.
Place the ping-pong ball on the surface of the water in the bowl
The
water does not get into the glass and the ping-pong ball is resting on the bottom
of the bowl.
The
air inside the jar finds a way of escape and rises upward. Now the water takes
up the space which has been left by the air
Bubbles
of air escape from the glass. These rise to the surface. Water gets into the
glass, the ping pong ball rises higher inside and the paper gets wet.
Immerse
the jar once again
When it touches the bottom, tilt it a little
Turn the glass upside down over the ping-pong ball.
Press down with the jar until it touches the bottom of the bowl
The
air in the glass stops the water from getting in and making the paper wet. Lift
the jar straight up out of the water and you will see that the paper is barely
wet, almost as if the jar has just been drained!
What
happens?
