We’ve looked at how objects absorb water before using sponges, underpants and even the good old walking water experiment. Today we’re trying an absorbing experiment with a twist and trying to halt the process as a way of investigating which materials absorb water and which don’t!
Absorbing Experiment Materials
- Sugar cubes
- Food colouring
- Aluminium foil
- Cling film
- kitchen roll
Add a few drops of food colouring to a little water and pour onto the plate.
Add a stack of sugar cubes and watch what happens. The coloured water should move up the stack of cubes and eventually make them collapse.
Try adding a small sheet of foil on top of one sugar cube and stack some more on top. Does this stop the water reaching the top cubes?
Try the same with some cling film, and some paper or tissue. Which work the best?
Can you try to predict which material will stop the water spreading through the cubes the best?
Which falls down first?
What’s happening to the sugar cubes?
The sugar cubes absorb the water as you can see by the colour rising up through the cubes. Our foil and cling film did stop the flow of water for a while, but eventually it found a way through. I think we cut the foil/clingfilm a little small. These were the last stacks to fall though.
The paper absorbed the water easily and let it reach the cubes above. This is because paper is porous and lets water pass through it. The foil and clingfilm prevent water passing through.
If you leave the sugar cubes for long enough they will dissolve completely!
Design an investigation thinking about how to make it a fair test. Think about the amount of water used, number of cubes and amount of material used to block the water.
Perhaps you could time how long each cube tower takes to fall!
Make it a Challenge!
Can you stop the tower toppling?
More absorbing experiments
Suitable for Key Stage 1 Science