C. Matter and Energy · Forces Causing Movement

Static Electricity: The Balloon Force

C2.1 A1.2 A1.4About 30 minutes

Learning goals

I can explain that static electricity is a non-contact force made by rubbing some materials together.
I can describe how charged objects can attract or repel other things.
I can give everyday examples of static electricity, including lightning.
I can do static electricity tests safely.

Words to know

static electricity
A non-contact force that builds up when some materials are rubbed together. It can pull or push things without touching.

charge
Tiny bits of electricity. Rubbing can move charge from one thing to another.

charged
Having extra (or missing) charge after rubbing, like a rubbed balloon.

attract
To pull toward.

repel
To push away.

lightning
A giant spark of electricity in the sky during a thunderstorm.

Zap!

It is a cold, dry day in January. You shuffle across the carpet in your socks, reach for the doorknob and... zap! A tiny shock. You pull off your wool toque and your hair stands straight up. Crackle!

These surprises are caused by static electricity.

What is static electricity?

Everything is made of tiny parts, and many of these parts carry tiny bits of electricity called charge.
When you rub some materials together (a balloon on your hair, socks on a carpet), some charge moves from one thing to the other. Now the objects are charged.
A charged object can pull (attract) or push (repel) other things without touching them. So static electricity is a non-contact force.
Static means "staying still". The charge stays on the object until it jumps off, sometimes as a little spark or shock.

A yellow balloon hanging over a wooden table, with small bits of white paper stuck to its bottom and more bits on the table, beside a wool scarf. — After the balloon is rubbed with wool, it is charged and pulls the paper bits up without touching them. That is static electricity, a non-contact force. AI-generated image

What you do	What happens	Pull or push?
Rub a balloon on your hair, then hold it near small bits of paper.	The bits jump up and stick to the balloon.	pull (attract)
Rub a balloon on your hair, then lift it slowly away.	Your hair rises up toward the balloon.	pull (attract)
Rub a balloon, then hold it near a thin stream of tap water.	The stream of water bends toward the balloon.	pull (attract)
Rub two balloons on your hair. Hang them side by side on strings.	The balloons swing away from each other.	push (repel)
Rub a balloon, then press it gently on a wall.	The balloon sticks to the wall for a while.	pull (attract)

Static electricity can pull and push

A rubbed balloon pulls small bits of paper up off the table without touching them.

Static electricity all around us

Shocks from doorknobs after walking on carpet.
Clothes sticking together when they come out of the dryer.
Hair standing up after you take off a hat.
Lightning! In a thunderstorm, charge builds up in the clouds. Lightning is a giant spark of electricity jumping from a cloud to the ground or to another cloud.

Static electricity happens most on dry days, like cold winter days. On damp, humid days it doesn't build up as much.

Lightning safety

Lightning is very powerful and dangerous. Remember: When thunder roars, go indoors! Stay inside until about 30 minutes after the last thunder.

Worked example

Let's read a static test

Sam wanted to know: Does rubbing a balloon more times make it pick up more paper bits? He used the same balloon and the same pile of tiny paper bits each time. He rubbed the balloon on his wool sweater, then held it just above the pile and counted the bits it picked up.

2 rubs: 3 bits
5 rubs: 8 bits
10 rubs: 15 bits

What changed? Only the number of rubs. Same balloon, same sweater, same paper bits, same height. It was a fair test.
Look at the pattern: 3, then 8, then 15. The numbers go up as the rubs go up.
More rubbing moved more charge onto the balloon, so the pull was stronger.

In Sam's test, more rubbing made the balloon pick up more paper bits. A stronger static force can pull more things.

Sam's results. Each time he rubbed the balloon more, it picked up more paper bits: 3, then 8, then 15.

Just for fun

What did the rubbed balloon say to your hair?

"I think I'm stuck on you!"

Hands-on activity

Balloon force lab

You need: a balloon (a grown-up blows it up and ties it), tiny bits of tissue paper or paper (about the size of your fingernail), a wool sweater or your own clean, dry hair, and a kitchen tap.

Hold the balloon near the paper bits without rubbing it. What happens? (Probably nothing.)
Rub the balloon on your hair or the sweater 5 times. Hold it a few centimetres above the bits. What happens?
Do Sam's test: try 2, 5 and 10 rubs, and count how many bits are picked up each time. Record your results.
Turn on the tap so there is a thin, smooth stream of water. Rub the balloon and bring it close to the stream (don't let it touch). Watch the water bend!
Rub the balloon and slowly lift it over your head. What does your hair do?

What to look for: the unrubbed balloon does nothing; the rubbed balloon pulls up bits, bends the water stream and lifts hair, all without touching. More rubbing usually makes a stronger pull.

Safety: a grown-up blows up the balloon. Balloons and broken balloon pieces are a choking hazard: never put a balloon in your mouth, and throw away popped pieces right away. Keep balloons away from babies and little children. Some people are allergic to latex balloons. Keep the balloon and electric things away from the water at the tap.

Your turn

How do you make static electricity with a balloon?

Is static electricity a contact force or a non-contact force?

A rubbed balloon is held near tiny bits of paper. What happens?

Two rubbed balloons hang side by side. What do they do?

What is lightning?

Why do you sometimes get a shock from a doorknob in winter?

What should you do if you hear thunder while playing outside?

More practice: warm-up

What do we call the tiny bits of electricity that move when you rub things?

Does an unrubbed balloon pick up paper bits?

Name one place you might see static electricity at home.

Does static electricity happen more on dry days or damp days?

Is a balloon safe to put in your mouth?

More practice: on your own

Your sweater and socks stick together when they come out of the dryer. Why?

A rubbed balloon makes a thin stream of water bend. Is the water pulled toward the balloon or pushed away?

In Sam's test, how many more bits did 10 rubs pick up than 2 rubs?

Your friend says static electricity can only pull. Is that true? Give an example.

Why is static electricity called a non-contact force, but friction is a contact force?

Challenge

After you rub a balloon on your hair, each hair can stand out away from the others. Use the word "repel" to explain why.

Compare a fridge magnet and a rubbed balloon. Give one way their forces are the same and one way they are different.

Why is static electricity a bigger problem in winter in Canada than in summer?

Check your understanding

Quiz

How can you give a balloon static electricity?

Static electricity is a...

A rubbed balloon is held above tiny paper bits. What happens?

Two balloons rubbed on hair are hung side by side. They...

Which is a giant spark of static electricity in nature?

When do static shocks happen most?

For parents and teachers

Big idea: Static electricity is a non-contact force (C2.1). Rubbing certain materials moves electric charge from one object to another; charged objects can attract or repel other objects without touching. Lightning is a large-scale example. Sam's test and the balloon lab practise fair testing (A1.2) and safe procedures (A1.4).

How to help: Winter is perfect for static! Point out clingy laundry, shocks from doorknobs and "flyaway" hair, and ask "What was rubbing?" You don't need to explain electrons; "charge moves when you rub" is the right level for Grade 3.

Common difficulties:

Thinking static only attracts. Show two rubbed balloons on strings repelling.
Confusing static electricity with electricity from wall outlets. Make clear that outlets are dangerous and are never part of these experiments.
Inconsistent results. Static is weaker on humid days; try the activity again on a dry day.

Safety: balloons are a serious choking hazard for children under 8 and around younger siblings. An adult should inflate the balloon, supervise, and discard any broken pieces immediately. Check for latex allergies. Teach the lightning rule: "When thunder roars, go indoors."