Colourful Sugar Cube Absorbing Experiment

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 to investigate 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 it 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. Add a small foil sheet on top of one sugar cube and stack some more on top. Does this stop the water from reaching the top cubes? Try the same with cling film, paper or tissue. Which works the best? Can you try to predict which material will stop the water from 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 through the cubes. Our foil and cling film stopped the water flow for a while, but eventually, it found its way through. I think we cut the foil/clingfilm a little small. These were the last stacks to fall through. The paper absorbed the water quickly and let it reach the cubes above. This is because the paper is porous and allows water to pass through it. The foil and clingfilm prevent water from passing through. If you leave the sugar cubes long enough, they will dissolve completely! Extension tasks Design an investigation by thinking about how to make it a fair test. Think about the amount of water used, the number of cubes and the 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 from 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 Foil stopping the top sugar cube absorbing water