In this experiment, you don't have to rely on the weather to see a rainbow!

A dimly-lit room
Torch
Sticky tape
Mirror
A tray, half-filled with water
Black paper
White card
Scissors
A grown up

Ask a grown up to help you make a small slit in the middle of the black paper with the scissors.

Tape the black paper to the end of the torch, making sure the slit is in the middle. When you turn the torch on, all the light should be blackened out, except a small beam shining through the slit.

Take the tray of water and lean a mirror inside it, on one of the tray's edges.

Point your torch so that the light beam shines under the water and on the bottom half of the mirror.

Hold up the white card in your other hand so that reflected light from the mirror shines on it.

You see a rainbow of colours on the white card.

When light travels through water, it slows down and bends. This is called refraction.

The colours that make up white light (the colours of a rainbow) all travel at different speeds, so they each bend at a slightly different angle. This makes the light separate into its seven different colours.

The mirror reflects the rainbow so you see it on the piece of card.