Skewer a balloon activity

You will need:

1 sharp wooden skewer
1 air-filled balloon

Instructions

Blow up a balloon - make sure that you don't blow it up too large.
Tie the balloon. Holding the balloon at the tied end, carefully push the wooden skewer through the opposite side. You should push the skewer through the center of the darkest part of the end of the balloon, i.e. where the balloon is least stretched, opposite the tied end. You may have to try it a few times to get it right but with practice you should be able get the skewer through most times.
Now push the skewer through to the tied end of the balloon and gently push the skewer point all the way through. Show it to your class, they'll love it!
Now, they have to work out why you can do it!

Aim the skewer for the center of the end of the balloon

Be Amazing!
How to teach science, the way primary kids love

Why does this work?

There are areas of the balloon which are more stretched than others.
If you try to pierce the balloon from the side, i.e. where it is most stretched, the balloon rubber will tear itself apart due to the elastic tension over the rubber. Piercing the bottom of the balloon is best place; the rubber has less elastic tension and the rubber itself will grip onto the skewer due to friction.

This is a great way to show that science can be found in sorts of places, even in sideshow acts where a magician uses 'magic' to get a skewer through a balloon.

Other friction experiment: Suspended rice bottle