Cut the tip (neck) of
the balloon off.
2. Allow an adult to cut the
lemon peel away from the lemon.
Using a large cut of lemon peel, make
the shape of a scuba diver, boat,
fish or missile.
3. Fill the jar with water all
the way to the top of the jar.
4. Place the lemon peel in the
jar of water.
5. Stretch the balloon to cover
the entire top of the mason jar and
use the rubber band to seal it in
place on the mouth of the jar.
Make sure that the balloon is stretched
tightly across the top and that it
is not loose or sagging.
6. Using your finger, gently press
down on the lid (balloon cover) and
watch your lemon dive to the bottom
of the jar.
7. When you release your finger,
watch as the lemon returns to the
top of the jar.
What happens to the lemon when you
press your finger on the lid of the
The pressure from your finger
squashes the tiny air bubbles in the
lemon peel allowing water in
which makes the lemon peel heavier
and causes it to dive down.
When you remove your finger, the
air in the lemon peel expands again
allowing it to float to the top (as
it becomes light again).