I propose we ..... put a needle through a balloon (without popping the balloon)

Links:

1.http://scifun.chem.wisc.edu/homeexpts/needle.htm
2.http://scifun.chem.wisc.edu/homeexpts/homeexpts.html

Materials:

• balloons


• long wooden or metal skewers


• pertoleum jelly a sharp pin


• cellophane tape

Procedure

1. Blow up a balloon and tie it close.


2. Take the skewers and dip the tip in the petroleum jelly, spread the rest of the jelly on the skewers.


3. Carefully take the skewer and push it gently through the balloon.


4. Push the skewer through the top and gnetly through the knot of the balloon.


5. With the skewer push it through in a twist motion.

Saftey Precautions:

• Be careful not the poke yourself with the skewers.

Scientific Principles:

The reason why the balloon pops with no petroleum jelly is because it breaks the long polymer chains in the rubber. The molecules in the balloon consist of cross linked polymers. When the tension on the cross-links is too much, the cross-links will break and pull-apart.