Unit 11, lesson 50. About 12 minutes.

Static electricity

Why does your hair stand up after you rub a balloon on it?

Play

Getting the experiment ready…

Explain

Rubbing a balloon makes it sticky.

It pulls your hair up.

Everything has tiny positive and negative charges. Usually they balance.

When you rub a balloon on your hair, tiny negative electrons move onto the balloon. This is static electricity.

Opposite charges pull together, and the same charges push apart. So your hair reaches for the balloon!

Rubbing transfers electrons, not protons. The balloon gains electrons and becomes negative, and your hair is left positive.

Like charges repel, and unlike charges attract. The force grows as the charges get closer.

Lightning is a giant discharge of static charge built up in storm clouds.

  1. Rubbing moves electrons
  2. Charge builds up
  3. Opposites attract
Want the full story?

The numbers of electrons in the sim are made up for the picture. Real rubbing moves billions of them. Some materials give up electrons more readily than others, so what happens depends on the materials.

Try it at home

Ask a grown-up to help

You need a balloon, small pieces of tissue paper.

You need: a balloon, small pieces of tissue paper.

Rub a balloon on your hair. Whoosh!

  1. Tear tissue into tiny bits.
  2. Rub a balloon on your hair or a jumper.
  3. Hold it near the tissue.

What's happening: the charged balloon attracts the tissue, even without touching it.

Balloons are a choking hazard. Keep burst pieces away from small children.

Physics is life

Your body

You can get a small shock.

You can feel a little shock after walking on carpet and touching a door.

Daily life

Clothes stick after a tumble dryer.

Clothes in a tumble dryer stick together because of static.

Nature

Lightning is giant static.

Lightning is a giant static spark, with enough energy to heat air hotter than the Sun's surface.

Space

Lightning happens on other planets.

Scientists have detected lightning on Jupiter and Saturn too.

Quick check

Question 1 of 3

What moves when you rub a balloon?

Words to know

Static electricity: Electric charge that has built up in one place.

Static electricity
Electric charge that has built up in one place.
Electric charge
A property of tiny particles that makes them attract or repel.
Electron
A tiny negative particle that moves around the nucleus.

Next up

Circuits: current, voltage, resistance