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
- Plate
- Water
- Food colouring
- Aluminium foil
- Cling film
- paper
- kitchen roll
Instructions
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. Check how many cubes the coloured water passes through before stopping. Ours only reached cube 3.
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!
Extension tasks
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
Can you waterproof a boot or a dinosaur?
Slightly different, but Tinkerlab has a brilliant activity where celery draws coloured water up through its stem. You can also use the same technique for making coloured flowers!
Suitable for Key Stage 1 Science
Investigating Materials
Last Updated on January 24, 2022 by Emma Vanstone
Very interesting. x
I’m sure the children loved watching the whole process but I’d be extremely interested to know how many 5 year olds were able to manage figuring out the cause for the sugar melting at different paces. It is within their grasp as I’m sure they’ve all handled kitchen paper, foil and cling film. Lots of children that age are smart enough to figure it out in those circumstances.
My main aim with these investigations is to spark an interest in why things happen. I’m not necessarily all that bothered that my children understand fully the reasons behind it. I just want them to be curious about the world.
we had soo much fun!
I like this idea! I was going to do the paper towel absorption experiment later today, now maybe I’ll do both!
Such a neat experiment!
its cool isn’t it?
The sugar cubes are ideal for your experiment! The water absorbing shows so clearly for children, and it adds a little bit of fun to the science experimenting that you are using both sugar and color—2 things children really seem to love!
Wow, great fun… my kids would want to eat it! Wonder if I could make them wait until the end of the experiment!
Thank you for sharing on Kids Get Crafty!
Maggy & Alissa
Yes I always remember sneaking the sugar cubes from my grandma’s bowl!
Fantastic experiment! Tempted to buy some sugar cubes now…
Do, because we shall be doing some more experiments with sugar cubes!
I love this, especially since the results are eatable and it’s very visual.
What a cool experiment!! My kids would love this! Thanks for sharing on TGIF! Have a great week,
Beth =-)
Thanks Beth!
the problem I encountered is that with most of the materials I tried, the bottom sugar cube collapsed well before the top cube got any moisture in it at all. so I turned the experiment upside down–stack two sugar cubes, lay a piece of plastic/foil/paper/fabric/whatever on top, then use an eyedropper to put water on top. this worked much better.
How long does this experiment take? I only have one hour with my kids and was wondering if the water will make it through the sugar by then.