Number 5: The rolling can

You can have a lot of fun with static electricity and here's a great example.

What you'll need.

• A balloon
• An empty drink can.  It needs to be aluminium. It may have a little sign on it that says ALU or try sticking a magnet to it. If the magnet sticks then its steel, if not then its probably aluminium.
• A hairy head (without any gel or hairspray) or a woolly jumper (thats a sweater if you are in the USA).

What to do.

• Blow up the balloon and tie a not in it.
• Rub the balloon against your hair (or woolly garment).
• Lie the can down on a flat surface.
• Hold the bit of the balloon that your were rubbing near the can.
• The can will roll towards the balloon!

What's going on?

Rubbing the balloon on your hair charges it up with static electricity which makes the balloon negatively charged. When you put the balloon near the can it pushes electrons (which are also negatively charged) to the other side of the can. This makes  the side which is nearest the balloon positively charged. Positive charges are attracted to negative charges so the can moves towards the balloon.