This role play helps pupils understand why they see objects as a particular colour and reinforces the concept of white light being composed of seven colours. It can also be used to help pupils understand how filters work. It works well with key stage 3 pupils and less-able KS4 pupils. Before starting, explain key terminology. For example, illustrate absorption by using a sponge under the tap, and reflection by bouncing a ball off a surface.
Sit seven pupils in a row in different coloured T-shirts. They will represent various objects. Give another seven pupils a piece of coloured card. The colours of card and T-shirts should represent the colours of the visible light spectrum. Next, encourage all the pupils holding cards to approach one of the pupils sitting down (the object). Some card colours will grab hold of the "object" (they are being absorbed) and the pupil carrying the card that matches the colour of the T-shirt will make contact with the "object" before turning and walking away (reflected).
Other pupils can make predictions about what they think will happen each time a different object is approached. Try different scenarios and when pupils are making correct predictions introduce pupils wearing black and then a white T-shirt.
This role play can be extended to help pupils understand how different coloured filters work. Scenarios can be set up with lines of pupils holding cards of the same colour to represent the filter. This time the seven pupils holding the cards representing the colours of the visible spectrum can approach the "filter". Pupils can be allowed through (transmitted) or stopped (absorbed) by the "filter".
Science co-ordinator, St Bernard's Catholic High School, Barrow in Furness, Cumbria