Wednesday, July 8, 2015

Frozen Salt Dough



Salt dough is one of the easiest activities possible. Just add salt, flour, and water.
For each cup of salt, add two cups of flour. Gradually add approximately 3/4 of a cup of water.
If you are colouring your salt dough, at the food colouring to the water before you mix it in.

We had a Frozen theme at work the other day so I decided to make some Frozen-themed salt dough. This is really simple: use blue food colouring and mix in a tonne of silver and blue glitter with the dry ingredients. It couldn't be simpler.
In no time we had salt dough that resembled Elsa's sparkling ice gown.



Afterwards, I had a look online and found some fantastic Frozen inspired playdoughs that might further inspire you.

Monday, July 6, 2015

Magic Mud - Cornflour Slime



One of my favourite activities is making cornflour slime, or, as some people call it, magic mud. It's super simple, educational, and most importantly fun! However, be prepared to get messy.

All you need is:

  • Cornflour
  • Water
  • Mixing bowl
  • Mixing spoon
  • Food colouring
Now, what to do:
  1. Start by pouring the cornflour into the bowl.
  2. Now stir in small amounts of water until you have a thick paste.
  3. Add as much food colouring as you like, but be warned, you will end up with coloured hands if you go crazy with it.
  4. Try stirring the mixture slowly. No to hard, huh?
  5. Now try it fast. This should be like trying to stir a solid; pretty near impossible.
  6. If you're game, try punching the slime hand and fast. It's like punching a wall.
Check out this YouTube video to see it in action:



So what's happening?
Well, when pressure is applied the viscosity of the slime increases and vice versa. This is called a shear-thickening fluid. The opposite happens to shear-thinning fluids like blood, paint, ink and nail polish. They get runnier when you stir them. The interactions between atoms in shear-thickening and shear-thinning fluids is so complex that no one really understands what is happening, except that it's pretty cool.
Hopefully this activity and its mystery can get you or your children engaged and interested in some science!


It does keep in the fridge for several days, but you might need to give it a stir to make it work properly again.