Enrichment Activity for 5-11 11-14
- Level Elementary
What you need
- Kitchen towels
- Non-permanent coloured felt tip pens
- Draw a dot in the centre of the kitchen towel with a felt tip pen. Black works well, but you can experiment with other colours
- Add a few drops of water to the dot
Results and Explanation
As the water spreads through the tissue, the coloured pigments that make up the ink separate out.
The differently coloured pigments are made up of different-sized molecules. This means that the water can carry them different distances across the paper.