KS3 · Physics

Static electricity

A rubbed balloon sticks to the wall. Touch a Van de Graaff dome and your hair stands on end. No glue, no magnets — just electrons on the move.

Charging by rubbing

1Two neutral objects23450Electrons moved onto the rod

Stage 1 of 5: Two neutral objects. Electrons moved onto the rod: 0. paused

Two neutral objects · 1/5Drag along the track and read each stage — keep an eye on the electron count.

Picture a rod and a cloth, each with just 8 positive and 8 negative charges (real objects have vastly more). Rod: 8 positive, 8 negative, so no overall charge. Cloth: the same. Neutral doesn't mean empty — it means balanced.

Rubbing moves electrons. Count the charges before and after.

What do you think?

Why is the cloth positive?

A rod is rubbed with a cloth. Afterwards, the cloth has a positive charge.

Why is the cloth now positive? Pick the idea closest to what you think right now.
How sure are you?

Push or pull?

What happens when two objects are brought close together?

Choose a route. Each pair of objects takes exactly one of them.

How many of the two are charged? → Same charge or opposite charges?

4 possible outcomes.

On Two objects, close together. 3 branches to choose from.

Charged objects push or pull on each other with an electrostatic force. Walk each route to see which.

Predict, then check

Commit to an answer before you reveal it.

A small ball hangs from a thread and carries a negative charge. You bring a negatively charged rod towards it, but stop a few centimetres away — they never touch. Then you slowly pull the rod further back. What happens?

The Van de Graaff generator

?

Reason it through

Why does touching the dome of a Van de Graaff generator make your hair stand on end?

Link 1 of 4

First link · your turn

Inside the machine, a rubber belt runs round and round, rubbing against rollers. What does all that rubbing do?

2
Locked — reveal the link above first
3
Locked — reveal the link above first
4
Locked — reveal the link above first

Static in real life

Problem or useful?

Put each example where it belongs, then read why static charge is involved.

Still to sort

A problem (0)

Static charge builds up where we don't want it.

Useful (0)

Static charge is put to work on purpose.

6 of 6 still to sort.

Static charge causes trouble in some places and does a job in others.

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

Rubbing doesn't make charge. It moves electrons from one object to another.

What you need to know

  • There are two types of electric charge: positive and negative. Most objects are neutral because they contain equal amounts of both.
  • In an atom, the positive charge is in the nucleus at the centre and the tiny negative electrons are on the outside.
  • Rubbing two insulators together moves electrons from one to the other. The object that gains electrons becomes negative; the one that loses them is left equally positive.
  • Charge builds up on insulators because it can't flow away. Metals are hard to charge by rubbing because charge flows through them and away.
  • Like charges repel, opposite charges attract, and a charged object attracts a neutral one. This electrostatic force acts without contact and gets weaker with distance.

The big picture

Everything is made of atoms, and atoms contain both positive and negative charge. Usually the two balance, so objects are neutral. When two insulators are rubbed together, electrons are forced off one and onto the other: the one that gains electrons becomes negative, and the one that loses them is left equally positive. Rubbing moves charge — it never creates it. Charged objects push and pull on each other without touching: like charges repel, opposite charges attract, and a charged object also attracts a neutral one. The force acts across the gap and gets weaker further away.

Key points

1Only electrons move when objects are charged by rubbing — the positive charges stay held in the nuclei.
2Gain electrons → negative. Lose electrons → positive.
3Rubbing moves charge; it never creates it. The total amount of charge stays the same.
4Static charge stays on insulators; it flows away through metals.
5Like charges repel; opposite charges attract; a charged object attracts a neutral one.
6The space around a charged object is its electric field: other charged objects there feel a force without touching, and the force is weaker further away.
7Static can be a problem (lightning, shocks, dust) or useful (laser printers and photocopiers).

Worked example

Problem

A balloon is rubbed on a woolly jumper and ends up negatively charged. (a) Which way did electrons move? (b) What charge does the jumper have? (c) Will the balloon be pulled back towards the jumper? (d) Why does the balloon also stick to a wall?

⚠ Watch out

Saying a positively charged object has 'gained positive charge'. It hasn't — it has lost electrons. The positive charges stay locked in the nuclei; only electrons ever move.

🧠

Memory hook

Electrons travel, positives stay home. LOSE electrons and you're left POSITIVE; GAIN electrons and you go NEGATIVE.

✓

Check yourself

A comb pulled through dry hair ends up negative. Which way did the electrons move, what charge are the hairs left with, and why might the hairs spread apart?

Flashcards

(14)
What are the two types of electric charge?
Positive and negative.
Why are most objects neutral?
They contain equal amounts of positive and negative charge, so the two balance out.
Where are the positive and negative charges in an atom?
Positive charge is in the nucleus at the centre; tiny negatively charged electrons are on the outside.
When objects are charged by rubbing, which charges move?
Only electrons. They're on the outside of atoms and easy to force off; the positive charge is held tightly in the nucleus.
An object gains electrons. What charge does it get? And if it loses electrons?
Gains electrons → negative. Loses electrons → positive (the same size as the charge the other object gains).
Does rubbing create electric charge?
No. It moves electrons from one object to the other. The total amount of charge stays the same.
Why does static charge build up on an insulator?
The charge can't move through an insulator, so it can't flow away — it stays put. 'Static' means still.
Why are metals hard to charge by rubbing?
Charge flows through a metal and away, so it doesn't build up.
What do like charges and opposite charges do to each other?
Like charges repel; opposite charges attract.
What does a charged object do to a neutral object?
It attracts it — like small pieces of paper, a drinks can or a thin stream of water.
Why is the electrostatic force called a non-contact force?
It acts across the space between objects that aren't touching. It gets weaker as they move further apart.
What is an electric field?
The space around a charged object, where other charged objects feel a force without touching it.
Why does touching a charged Van de Graaff dome make your hair stand up?
Each hair gains the same kind of charge, so the hairs repel each other and spread apart.
Give one problem and one use of static electricity.
Problems: lightning, static shocks from clothes or carpets, dust sticking to surfaces. Uses: laser printers and photocopiers, which attract toner to the right places.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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How this lesson was checked. This KS3 Physicslesson was published through Lightbulb Learning's human-designed editorial process — the educational standards, accuracy rules and publication checks it must pass were authored and approved by Philip Halpin. It passed subject-specific assessment, automated educational checks and technical publication verification before going live (publication checks completed 30 September 2026). Published pages are monitored, human spot-checking is ongoing across the lesson library, and anything found wrong is corrected or withdrawn. How our lessons are made and checked. Spotted a mistake? Email hello@lightbulblearning.co and we'll review it.