Students use colourful experiments to investigate the properties of colour and its use in chemistry.

If you teach primary science, see the headings below to find out how to use this resource:

Skill development

Children will develop their working scientifically skills by:

  • Drawing conclusions and raising further questions that could be investigated, based on their data and observations.

Learning outcomes

Children will:

  • Use knowledge of solids, liquids and gases to decide how mixtures might be separated.

Concepts supported

Children will learn:

  • The colour of inks and other coloured objects can be made up of a mixture of multiple colours and dyes.

Suggested activity use

This activity can form the basis for a group discussion where children look at how dyes and colours in pens and sweets are made. Alternatively, the resource can be used to generate questions and discussions around the topics of light, or dissolving and reversible changes.

The activity shows children how chromatography can be used as a separation technique – in this case as a way of separating mixtures of dyes and colours.

Practical considerations

It may be best to test different pens ahead of the lesson(s) in order to determine which ones give the best results.

Also, it may be difficult for primary schools to source the necessary equipment for the traffic light activity, in particular the sodium hydroxide pellets.