Image right: Static electricity from a balloon really makes an empty soda can move! Credit: NASA
You will need:
empty soda can
string (if you like)
Here's what you do:
1. Blow up the balloon.
2. Rub the balloon on your head. This makes an electrical charge.
3. Lay the soda can on a smooth floor.
4. Bring the balloon close to the can.
5. Look at what happens.
6. Have a race with a friend with two cans and two balloons. See who can move the can across the room first, without touching it.
7. Try rubbing the balloon on your hair and then sticking it to a wall.
8. Tie string to the ends of two balloons that you have blown up.
9. Rub the two balloons together.
10. Hold them by the strings right next to each other.
11. Watch what happens.
Image above: Static electricity makes your hair stand up Credit: NASA
Image above: Static electricity makes the can move Credit: NASA
Image above: Static electricity moves one balloon away from the other Credit: NASA
How did you do that?
This happened because of static electricity. Have you ever walked across the carpet and then touched something and gotten a shock? That is static electricity, too. This is caused by electrons. They are so small we cannot see them.
Rubbing the balloon takes electrons from your hair to the balloon. Now the balloon has a negative charge (-). The can has a positive charge (+). They are opposites. This makes the balloon pull the can towards it. Shuffling your feet across the carpet also picks up electrons. When you touch something with a positive charge, it makes a little electricity jump from it to you.
If you rub two balloons together, they are both negative. They repel each other or push each other apart.