# GCSEs

## Classifying stars by colour

Stars can be classified according to their colour and a starâ€™s colour is related to its surface temperature. The colours ...

Although ionising radiation can be very useful, it can also pose some very serious dangers. The generation of electricity using ...

## Density and pressure

Density Density is a measurement of the amount of mass per volume of the substance. It is vital that you ...

Photographic film Henri Becquerel was the scientist who discovered the effects of radioactivity. Becquerel was conducting experiments to investigate the ...

## Distance, length, time and speed

Distance and length We will begin this unit by getting to grips with some mathematical calculations on distance, time and ...

## Distance-time graphs

We have looked at the relationship between speed, distance and time, so now we can expand on these ideas using ...

## Elastic and inelastic collisions

When objects collide, their momentum is converted into other forms of energy such as heat or sound. If this does ...

## Electrical charge

The creation of electrical charge is a fundamental part of electricity. Most electrical charge is produced due to the movement ...

## Electrical resistance

All components that have a circuit offer some resistance. This is because each component resists the flow of electricity to ...

## Electricity wires

This part of the chapter focuses on the use of mains electricity. Electricity is used for many things that are ...

## Electromagnetic induction

When a coil or a conductor is moved through a magnetic field a voltage is induced and current will flow. ...

## Energy efficiency

Energy is used throughout our daily lives, in our homes, the buildings we work in and on our roads. This ...

## Electromagnetism

A magnetic field is also produced around any electrical conductor when current is flowing. For example, a magnetic field is ...

## Energy resources

We use energy in different forms every day to provide us with the necessities we need to survive such as ...

## Energy transfers

Energy is measured in the unit joule (J) and is needed by all objects to change shape, size or position. ...