That’s right, we’re doing that very important, ultra-serious experiment – we’re making cornflour gloop!
What you’ll need:
- Mixing bowl
- Food colouring (optional)
How you do it:
- Add your cornflour to the bowl and then add about half as much water.
- Stir until mixed in.
- Add a little more water or flour until you have a strange paste. The paste should be difficult to stir.
Okay then chemistry sleuths…
- What happens when you tap it with your finger?
- Can you pour it?
- Can you roll it into a ball?
When you dispose of the gloop, don’t just pour it down the drain! Dilute the mixture with lots of water first then pour it away. Or put the mixture in a bag and put it straight in the bin.
So, what’s going on?
Think of the Olympic stadium, full of visitors anxious to get to the next event. If you try to run through the crowd, you’ll quickly find yourself bumping into people and causing a pile-up.
The most efficient way to get to the event is to move slowly through the crowd, twisting and turning past people.
Cornstarch molecules are big and act like a crowd of people: they move slowly round each other in water. If the movement is too fast the big starch molecules bunch together giving the solution ‘solid’ properties.
As with all science experiments, make sure you have a responsible person supervise you at all times. And remember to have fun!
Kareena’s Chemistry is supported by the Royal Society of Chemistry