Electrostatic Slime - Science you can do at home!

See how a balloon can stop a substance from being poured with just a balloon, cornstarch and vegetable oil! All things that you can find at home, so go on grab some vegetable oil and cornstarch from the cupboard and a balloon from your last birthday party (or make a quick trip to your nearest supermarket) and get ready for some sciency fun!

Mix equal amounts of vegetable oil and cornstarch powder into a cup - so if you put a quarter of a cup of vegetable oil then you need a quarter of a cup of cornstarch powder added to this. Then stir with a spoon and that's it! You've made your electrostatic slime!

Now grab that party balloon and rub it in your hair or a woolly jumper - you've now charged the balloon (more science talk is on its way). Now start to pour your slime into another cup and then bring the balloon near the slime and watch it get attracted towards the balloon and you may even see it stop pouring! 

Here's some successful electrostatic slime:

Slimey Science

When you rub the balloon in your hair or against your woolly jumper electrons from your hair/jumper are rubbed off onto the balloon by friction. Thus, the balloon gains a negative charge and your hair becomes positively charged and you know that like charges repel and opposite charges attract - this is why your hair suddenly becomes attracted to the balloon! 

But how does the slime get attracted to the balloon without touching it?! Well, what we have made is a substance where the solid cornstarch particles are 'swimming' in the vegetable oil and in the presence of an electric field - the region around a charged object (the balloon in this case), the viscosity or how runny the substance is changes. Near the balloon the substance becomes less runny and this is what makes it stop pouring - in sciency terms the slime is called a electrorheological liquid (people will think you are a super genius with that term!) 
These types of fluids are used in some brakes where a 'voltage' is applied to change the runny-ness of the fluid.  

But in greater detail we know that atoms contain electrons and so the negative charge of the balloon pushes the electrons in the 'cornstarch atoms' away and then we get a 'net' positive charge of the slime on the side closest to the balloon and so the slime moves towards the balloon due to what is called 'electrostatic' attraction,  as shown below:

Get making and spread some science!