Light is actually made up of a spectrum of colours each with a different frequency. One way to see the spectrum of colours is to use a prism to split the light.
What is a prism?
A prism is a triangular block of glass or perspex which splits light into its constituent colours.
When light enters a prism it is refracted. Each colour of the spectrum is refracted by a different amount meaning the colours are dispersed ( spread out ) allowing you to see them.
A prism is a great way to demonstrate visually that white light is actually made up of 7 different colours.
How to split white light with a prism
What you need to split light
Large sheet of white paper
Dark coloured cardboard
Tape or glue
Large tray or sheet of thick card
How to use a prism
On a sunny day this is a great way to split light with a prism.
Use the dark card to create a slit over a sheet of white card. Place the card so sunlight shines through giving a thin beam of light.
Place the prism over the light and rotate it until you can see the light split into the spectrum of colours.
Why does a prism split light?
White light, which enters the prism, is a mixture of different frequencies, which get bent ( refracted ) differently thought the prism, allowing them to be seen separately.