Balloons That Stick to the Wall
- Physics
- Ages 8–11 · Grades 3–5
- Hands-on experiment
What you’ll find out
- Rubbing moves tiny charges between materials, leaving one negative and the other positive.
- Opposite charges attract and like charges repel, without touching.
- Static charge leaks away, and can jump as a small spark.
No sign-up and no real names. In the lesson you check your understanding as you read, run the experiment yourself, and practise until it sticks.
Rubbing moves tiny charges
Rub a balloon on your hair, then lift it slowly. Your hair stands up and follows the balloon! Hold the balloon against a wall and it sticks there on its own. Rubbing moves tiny particles called electrons from your hair onto the balloon. The balloon now has extra electrons, and your hair has too few. Things with opposite charges pull on each other, so your hair reaches after the balloon. This is called static electricity. It works best on a dry day.
Like pushes like
Rub two balloons the same way and hang them side by side on threads. They swing apart! Both have extra electrons, so both are negative, and two things with the same charge push each other away. Now hold a rubbed balloon over tiny bits of torn paper. The paper jumps up to it. Static charge does not last. It leaks away into the air, and it can jump all at once as a tiny spark. Lightning is the same thing, but enormous.
Curriculum links: NGSS 3-PS2-3