States of Matter, Non-Newtonian Fluids, and Ultra violet absorption - Oh My!

This week we explored states of matter, how we describe them, how we can change states and made GLOWING Oobleck!

First off we experimented with states of matter using chocolate! We took solid chocolate and investigated its properties, does it flow? can I hold it in my hand? what happens when I apply force to it? i.e. bite it.
We then added energy, in the form of heat to see what happened...
Of course, the chocolate melted giving us a liquid. We then investigated the properties of the liquid chocolate (Let the chocolate cool a little first!).
We then compared the two states of chocolate, how they were different and why we think this is. We also compared the chocolate to the air around us and tried to create rules for what makes a solid, a liquid or a gas.

Next, we made some glowing Oobleck!
Oobleck is  a non-Newtonian fluid, because it doesn't conform to Newton's Laws of viscosity. Oobleck is a fluid that acts as a liquid when at rest but when you apply pressure to it, acts as a solid! For an extra glowing surprise, you'll need to use tonic water with quinine and a UV torch (more about that later!).

Warning! This will get MESSY. Best to do this outdoors in old clothes!

You'll need:

• A measuring cup
• Cornflour/ Cornstarch
• A mixing bowl
• Water
• A spoon or something to stir with
• Food colouring (if you're feeling fancy)

First you need to measure a cup of the cornflour and pour this into your mixing bowl. 

Next slowly add in the water (or tonic water if using), and a few drops of food colouring, stirring as you go until you reach a consistency resembling thick custard. 

The mixture will become very hard to stir but keep going! We found that the most effective way was using our hands, this is also a great way to experience the unique texture of the Oobleck.

Once the cornflour and water are combined you can play with your Oobleck! Can you create rules for how Oobleck behaves? How is this different or similar to solids or liquids?

Get set, GLOW

Now it's time to see if the Oobleck glows, this will only work if you made the Oobleck using tonic water with quinine, and if you've used food colouring this can effect the intensity of the glow. 

Shine your UV torch (These are available on Amazon for less than £5) over the Oobleck in a darkened room to see it glow! The tonic water on its own will also glow. 

Why does this work?

The quinine in the tonic water absorbs UV light, which is invisible to us, and emits visible light. We perceive the visible light emitted as the 'glow' we see. 

Have your kids got a burning science question that can't wait until they go back to school? Let me know! I'll try my best to answer them. 

Get in touch with me on Facebook and Twitter for more science experiments and tutorials! 

Also check out the Slow Mo Guys on YouTube, they have some great Oobleck videos!