Mixing Materials

We are learning about materials this term and we are finding out what happens when you mix solids and liquids. Today we investigated what happens when you mix cornflour and water together.

First we mixed the water and cornflour together.

 

We used our hands to make sure it was mixed together properly

 

Things started to get very messy!

 

We found that the mixture behaved in a very surprising way. When we picked it up, it felt solid and we could roll it into a ball. However, once we let the mixture go, it changed back into a liquid again. It felt very strange and everyone wanted to have a go at holding it and letting it go. The classroom soon started to look very messy with cornflour mixture nearly everywhere (except in the bowls!).

 

 

 

 

We found out that the mixture is called a non newtonian fluid. The cornflour and water do not actually mix. Instead the cornflour molecules are suspended in the water. When you force the molecules together, it creates a solid. As soon as the pressure is taken away, the material turns back to a liquid.