Now I have tagged this as contained mess but this perhaps depends on what your child is like… Mine has her moments but is generally quite calm. I showed the photos to my lovely cousin (in law – is that a thing?!) and she questioned why there wasn’t an enormous patch of goo on my carpet. So if you don’t like kids and mess together then this might be best saved for warmer days outside? Or done in the bath (naked?!)? Or perhaps even avoided all together! However it can be contained quite well and the ingredients have the advantage that they are really easy to clean up (they just dissolve in water). Plus I genuinely thought it would create more mess than it did. However, the activity also has a huge advantage that it is super fun so they are almost too engrossed in that to create too much havoc (I say almost as am sure there are some children that would still create havoc!).
It’s a really easy one in terms of things you need. I actually had all of the ingredients in the cupboard this time. But thought I didn’t so now have a lot of cornflour. This is the kit:
- cornflour (essential)
- water (essential – useful to have a jug to pour it in)
- big bowl (essential – the bigger the bowl the less mess perhaps?!)
- wooden spoon (not essential but helps with the mixing)
- food colouring (not essential but makes it look nicer/more like goo)
And this is how you do it:
- Add 2 cups of cornflour into bowl
- Add food colouring (if using) to a cup of water and add water to bowl
- Mix (slowly)
- Play! Basically squish it, hold it up and let it drip down, roll it, scoop it up, push, pull etc. It is such a strange substance both my daughter and husband couldn’t stop playing with it.
The science bit
The cornflour goo is made up of long stringy particles. This enables it to act like a liquid and a solid. When you hold it up and let it drip down the long particles slide over each other, making it appear like a liquid. When you squish it the particles resist this and the goo feels solid.
Explaining it to children
We talked about things we could think of that were solids (stones, wood, glass) that when you pushed against them they felt hard, and liquids (like water or milk) that dripped down when you poured them. We then also thought about whether you could pour the solid things and how they would act differently to the liquids if you did this, and if you could push against the liquids and what that feels like. I explained this special cornflour goo was acting like a solid and a liquid at the same time, which made it unusual because things didn’t often do that.
I did’t go into particles with my daughter but you could. You never know what they might understand until you try. If I had I would have tried to relate them to something they know or can visualise, i.e. particles are like grains of sand (except they are so small we can’t see them) but these ones are long and thin like a long bit of string or hair.
Again my 1 year old was asleep while we did this, but he was pretty fascinated with what everyone was doing when he woke up. I didn’t let him play with it though, pretty sure we would have got it all over the carpet if we had done!
Experiment based on an activity from the fantastic Usborne Activities: 365 Science Activities book.