PRISMS Draw a diagram showing the dispersion of white light as it passes through a prism.

How do we get rainbows? Rainbows occur in the sky after rain. They form when sunlight passes through the raindrops. The drops split the white light from the sun into a spectrum of colours. The colours that make up the spectrum are red, orange, yellow, green, blue, indigo and violet. (ROY-G-BIV) This is called dispersion.

What colour is light that looks white? Light that looks white is really a mixture of every different colour, jumbled together so thoroughly that you can’t see any of them seperately. When sunlight shines through raindrops or bounces off the back of a CD, the hidden colours fly apart and reveal themselves in a rainbow pattern.

Why Do Colours Exist? Colours exist because light waves can be different lengths. If the waves a LONG, we see them as red. If the waves are SHORT, we see them as blue. Light waves are very short, even in red light. About 2000 waves stretching end-to-end would fit along a millimetre.

Prism Experiment https://www.youtube.com/watch?v=KgqV975EtA0 Set up your raybox on your science book. Shine a full beam of light onto a triangular prism and turn the prism until the spectrum of colours is formed. Draw a diagram showing your observations (use coloured pencils to show the spectrum of colours)

Newtons Prism Draw a diagram showing your experiment with the two prisms and illustrating the result.

Next Lesson Colour – explain why an object appears to be a certain colour Explain how a filter changes the colour of a light seen. Describe two ways different colours can be seen.