Friday, 12 June 2015

Rowan's Science

Year 3 have been learning about how materials can have the properties of more than one state of matter. In this lesson they were using cornflour and water to create a thixotropic substance.

"This means that when you squeeze it it is like a solid, but when you let go it becomes all runny"
Georgia Chilvers

If you want to try this at home, here is the recipe:

Materials:
  • Cornflour (Cornstarch)
  • Water
  • Large bowl and spoon
  • food colouring (optional)
Directions:
Pour your cornflour (or cornstarch) into a large bowl. You will need at least double the amount of cornflour to water. (So, if you have 2 cups of cornflour, you'll add approx 1 cup of water, but experiment with this, that's the fun part!)

Add some food colouring to your water.

What not to do:
Do NOT add a lot of blue food colouring. Your hands will end up stained. You should use no more than 4-5 drops.

Slowly add your water to your cornflour ensuring not to add more than half the amount of water to cornflour ratio.

Give it a stir part way through. This is a fun part of the experimenting. It allows the children to see what is happening at this point and make decisions as to whether more water is required or not.

You will know when your slime has all come together. It should be easy to stir slowly and flow like a liquid but try giving it a fast stir and see what happens!




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