Testing dyes
Explore how a range of different colours can be achieved through dyeing and find tests you can try at home in this article from the ‘Avogadro’s lab’ series.
A substance that reflects all wavelengths of visible light appears white, whereas a substance that absorbs all of those wavelengths appears black. To appear coloured, a substance must fully reflect or transmit only some of the wavelengths of light falling on it. This can be done using a structure, as in the case of DVDs and the Morpho butterfly, or by using molecules that absorb some wavelengths more than others.
Such molecules fall into two broad groups: dyes and pigments.
There are a number of experiments that you can be carry out using natural dyes and some clean samples of either cotton or wool – read on to find out more.
Make your lessons pop
Choose an account option to continue exploring our full range of articles and teaching resources