New
New
Year 8

Static electricity: charge

I can describe what charges are and how they are transferred between some objects, giving them opposite charges.

New
New
Year 8

Static electricity: charge

I can describe what charges are and how they are transferred between some objects, giving them opposite charges.

Lesson details

Key learning points

  1. Atoms contain positive and negative electric charges
  2. The particles in atoms with a negative electric charge are called electrons
  3. Electrons can sometimes be rubbed off one object onto another, depending on what the objects are made of
  4. It is hard to charge something made of metal because electric charge flows through metal, stopping charge building up
  5. When static electricity builds up, it can be useful but also a problem

Common misconception

Pupils often think that both positive and negative charges can move when objects are charged by rubbing.

Emphasise that only electrons can move, explaining that they are found on the outer part of atoms. Use this to explain how a positive charge is created by the removal of electrons.

Keywords

  • Atom - Atoms are the particles that make up chemical elements containing equal numbers of positive and negative charges.

  • Positive charge - A type of electrical charge that is attracted to a negative charge.

  • Negative charge - A type of electrical charge that is attracted to a negative charge.

  • Electron - Electrons are the negative charges in conductors that flow to produce an electric current.

When using electrostatic generators, consult the CLEAPPS guidance and follow it.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
In which of the following examples could you find static charge building up?
Correct answer: car tyres rubbing on the road
Correct answer: rubbing a cloth on a piece of plastic
mains electricity lighting a bulb
Correct answer: walking on a carpet with rubber soled shoes
Q2.
What is the charge shown on the balloon?
An image in a quiz
positive
neutral
Correct answer: negative
Q3.
A ruler and a balloon both have a positive charge. Which of the following will happen as the ruler is brought closer to the balloon?
An image in a quiz
They will attract more strongly.
They will attract more weakly.
They will repel more weakly.
Correct answer: They will repel more strongly.
Q4.
The balloons shown both have a negative charge. Which of the following will the balloons do when brought close to each other?
An image in a quiz
attract
Correct answer: repel
move up
move down
Q5.
Which of the following explains why the balloon shown sticks to the wall?
An image in a quiz
Correct answer: The positive and negative charges attract.
The balloon contains helium.
The rubber of the balloon is sticky.
Friction between the wall and the balloon keeps it in place.
Q6.
Which of the following explains why static charge does not build up in normal circuits?
There is a different type of charge in electrical circuits.
The circuits are not rubbed.
The electrons carry away the charge.
Correct answer: Charge is able to flow away through conducting wires.

6 Questions

Q1.
In a conductor, negative charges called can flow to give an electric current.
Correct Answer: electrons, electron
Q2.
A neutral object is rubbed and becomes positively charged. Which of the following is the correct explanation for this?
The object gains negative charges.
Correct answer: The object loses negative charges.
The object gains positive charges.
The object loses positive charges.
Q3.
Which of the following correctly explains why is it difficult to charge an object that is made of metal?
Metals do not have electrons.
Correct answer: Electrons flow easily through metal, so charge cannot build up in one place.
Electrons are more strongly attached to atoms in metals than in other materials.
A metal always gains or loses the same number of positive and negative charges.
Q4.
Which of the following statements is correct for a neutral object?
The object must be an insulator.
The object must be a conductor.
The object contains no electrons or nuclei.
The object contains nuclei but no electrons.
Correct answer: The object contains equal amounts of positive and negative charge.
Q5.
A Van der Graaf generator has a moving rubber belt which becomes charged by friction. The charge is transferred to a metal dome. Why can the dome become charged, even though it is made of metal?
An image in a quiz
Correct answer: The dome’s support is plastic, which is an insulator.
The dome’s support also becomes charged.
The dome’s support is metal, which allows charge to keep flowing to the dome.
Q6.
A person puts their finger near the dome of a negatively charged Van der Graaf generator. A spark travels between their finger and the dome. Which of the following statements correctly explain why?
Atoms travel between the person and the dome.
Nuclei travel between the person and the dome.
Correct answer: Electrons travel between the person and the dome.
Correct answer: A current flows between the person and the dome.