Please see below for some photos and Instructions!!
We did a cool science experiment with a balloon today!
1. Inflate your balloon until it is 3/4 way full of air.
2. Tie a knot in your balloon so the air doesn’t escape.
3. Look at both ends of your balloon. At the very tip and at the knot the balloon is darker in colour and less stretched.
4. Put some petroleum jelly on a wooden skewer and push it the whole way through the balloon (in through the darker tip) and out through the other end right beside the knot.
5. Did your balloon pop?
6. Try this again, except try pierce a fully inflated balloon through the side. What happens?
What is happening?
Balloons are made of rubber and when they are blown up the rubber is stretched out. Rubber is made up of tiny microscopic strands and chains of molecules called polymers. When the balloon is blown up these polymers are stretched out and are put under a lot of strain and pressure to hold all of the air in the balloon.
When a pin or sharp skewer pierces the stretched polymers it bursts and causes a pop. However, at the very tip of the balloon the least amount of strain or stretching is happening to the polymers so a skewer can carefully be pushed through the balloon without it popping!