Electricity... tackle the tricky bits
All you need to know to confidently tackle common misconceptions, the science behind electricity and how to teach it to children in a way they will really understand.
Electricity is a topic open to misunderstandings, in part because it is an abstract concept. Although its effects are observable (like forces), it is itself invisible thus fertile ground for misconceptions.
Here we focus on those scientific concepts that are the hardest to explain to children. We break it down into what pupils need to know and outline the background science. Even though much of the background science does not need to be taught to primary aged children, it is useful for you as a teacher when addressing misconceptions and children’s challenging questions.
Please refer to your national curriculum documents when planning your sequence of work and ensure that you teach the correct knowledge for your year group.
What do children need to know about electricity?
Pupils need a basic conceptual understanding of electricity to support their learning, which should be as exploratory, hands-on and pupil-led as possible. We have included some ideas for how to teach electricity in part two of this topic guide.
Key scientific concepts: Pupils need to...
Understand that electricity is a type of energy that powers electrical appliances
Apply an understanding of how electricity works to building working circuits and compare and explain variations in what they observe
Identify materials that are good conductors and insulators and know how to stay safe when using electrical equipment
1. Electricity is a type of energy that powers electrical appliances
Pupils need to know:
Electricity is an energy obtained in different ways:
by burning fossil fuels (e.g. coal, gas) or using nuclear energy in large power stations to produce superheated steam that spins huge turbines to generate electricity
by using hydroelectric or renewable sources (wind, wave, solar) to directly move turbines
All of these methods convert kinetic (motion) energy into electrical energy. It is then transported around the country via the national grid and then into our homes through large wires and cables.
2. Build working circuits and compare and explain variations in what they observe
Pupils need to know:
The names of basic parts of an electrical circuit and how to build a simple series circuit
Electrical energy flows around a circuit (or loop) made of metal wires when a battery has both ends connected and the circuit is complete
A circuit is complete when a battery has both ends connected
Energy is already present within the wires, rather than travelling from the battery (which merely acts as a sort of push), so any components in the circuit (bulb, buzzer etc) work instantaneously
Components in the circuit will continue to function until the loop is broken, such as by a switch being turned off
How to represent a circuit using the correct symbols
Children do not necessarily need to be able to explain what electricity is, or even use many of the technical terms. But what happens inside those wires is important for you to know.
All materials are made up of tiny particles called atoms, which have protons and electrons inside them. Protons have a positive charge. Electrons have a negative charge. They are attracted to each other and each carries an electrical charge. A bit like bumper cars, a free electron bumps into the next atom, transfers its charge and pushes off another free electron.
Electricity is the flow of an electric current caused by the movement of electrons.
Electrons moving within a closed (or complete) circuit is therefore how electrical current is generated. When you switch on a torch, you are closing a circuit allowing the electrons to move and generating electricity that flows around it. This is exactly what the children experience when they create a simple series circuit using a battery (a collection of one or more electrical cells), two wires, a switch and a bulb.
When the circuit is closed:
The electrons move through the wires
Electric charge flows continuously: away from the negative side of the cell to the positive side until the circuit is broken
The bulb lights up instantly because the electrons are already present throughout the circuit (i.e. they are already in the wires) and the cell simply acts as a kind of ‘energy push’
It is important to note that the bulb lights up because as the electrons pass through the filament some of the electrical energy is converted into heat and light energy.
3. Identify conductors and insulators and use electricity safely
Pupils need to know:
Metal is a good conductor because it allows the electrical energy to pass through it easily
Insulators, such as plastic and rubber, do not allow electrical energy to pass through them easily. This is why wires in most common appliances are covered with a protective plastic coating.
Using electricity safely: Properties of certain materials
The easy flow of electrons is only possible in certain materials, which are called conductors. In metals, the electrons are free to move, which means they are good conductors of electricity. Materials, such as plastic, paper and rubber, that do not allow electricity to flow easily through them are called insulators.
Using electricity safely: Voltage
Voltage is like the pressure from an electrical circuit's power source (e.g. a battery) that pushes charged electrons (electrical current) around the circuit. The greater the voltage (or the greater the number of cells) in the circuit the greater the size of the electrical current and therefore the power being generated. Larger appliances require a higher voltage to be able to work and are therefore more dangerous to use.
Ultimately, of course, using electricity safely is a matter of being cautious and following the necessary guidelines. Please refer to CLEAPSS or SSERC for advice on health and safety.
Ideas to try with your class
Now you've got the key concepts under your belt, try our ideas to help you explain electricity to your class in a way they will understand, in part two of this topic guide!
You can also take a look at the related topic guides for light, materials and forces.
Image credit: Blue insulation tape with pliers and amp meter by asadykov via Shutterstock