You will need:

• Cornstarch (Cornflour)
• Water (2 cups of cornflour to 1 cup of water)
• Food colouring (optional)
• Bowl

What to do:

1. Mix all of the cornstarch with some water, containing the food colouring if you're using some, with your hands until it resembled liquid.
2. When touched and grabbed with your hand, it should turn into a solid. You will need to mix for about 10 minutes.
3. The mixture will look like a liquid and move from side to side when the bowl is tilted.
4. Try to punch or grab the liquid into a ball. What happens?

How does it work?

When you apply pressure to the cornstarch either by trying to punch the liquid or grab the liquid into a ball, the fluid mixture suddenly becomes a solid. This is due to the sudden pressure your hand is applying to the mixture. Pressing your hand slowly through the mixture allows the mixture particles to move out of the way but sudden movements, like punching the mixute, do not allow the particles to slide past each other and out of the way of your hand.

Viscosity is a term used to describe how easily a liquid will flow when poured from a container. Water flows easily. Honey, at room temperature, has a high viscosity and flows more slowly than water. However, if you warm honey up, its viscosity drops and it flows more easily. Most fluids behave like water and honey - their viscosity depends only on temperature. We call fluids like water "Newtonian Fluids" since their behaviour was first described by Isaac Newton.

The cornstarch mixture is "non-Newtonian" since its viscosity also depends on the force applied to the liquid or how fast an object is moving through the liquid.

Other examples of non-Newtonian fluids include ketchup and quicksand. Quicksand is like the cornstarch mixture - if you struggle to escape quicksand, you apply pressure to it and it becomes hard, making it more difficult to escape!

Don't forget to take some pictures of your Non-Newtonian fluid and send them into us to be in with a chance of winning some great prizes.

The School of Chemistry at NUI Galway advise that adult supervision is needed for all experiments. The portions of materials used in the experiments should not be increased from that described and mixtures prepared should not be ingested. The full text should be read before starting any experiment.

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