Tuesday 24 October 2017

Making Magic Potions! - This week we're talking density.

Making Magic Potions! - This week we're talking density

Halloween is almost here! Why not try mixing up some magic potions? 👻💚😀

The science bit

Density is mass per unit volume, that means that to work out how 'dense' a liquid is you divide its weight by the area it takes up for example if a substance weighs 10g and has an area (that's the length x width x depth) of 2cm³ it has a density of 5gcm³.
Ok, that was complicated, but think of it like this, water is less dense than syrup. If you have 2 bags 1 filled with syrup, the other filled with water but both have the same amount of liquid which will be heavier? It's the syrup - there is the same amount in the bag but it weighs more because the syrup is denser.
So, other than filling bags with fluids (fun, but messy) how can we see which liquids are denser? Try this magic potion experiment to find out!

Making magic potions

You will need:
  • Water
  • Oil
  • Treacle
  • Golden Syrup 
  • A clear container, with a lid
  • Optional extras: glitter, food colouring, plastic toys of different weights.

First of all, we need to add our different substances to our container, try to use equal amounts of each liquid to make this a fair test - What do you think will happen?
I like to add food colouring to the water to make this extra magical, you could also add glitter or sequins! 

Now have a look at the different layers that will form in your container, at the very bottom is the densest liquid and at the top the least dense. Make a note of the order the liquids settle in, from least dense to most. (Spoiler alert!: Oil < Water < Syrup < Treacle). 

Now try turning your container upside down - What happens? do the layers stay the same or do they change? You can check this by looking at what you noted down in the last step!
For extra fun and a nice spooky effect, try adding some plastic toys of different weights, do they sink or float? Or do they hover in the middle? What do you think this means? Let me know on Twitter! You can also send your pictures of your experiments to our Facebook ðŸ‘»

Happy Halloween! 

Sarah 💚