Mixing fresh and salty water
You will need:
- 2 jugs
- tall drinking glass (the narrower the better)
- salt
- spoon
- 2 colours of food colouring
Method:
- Fill both jugs with water. To one add a handful of salt and stir until it dissolves. Keep adding salt until you can get no more to dissolve. Stir in some food colouring.
- Add some of the other food colouring to the other jug.
- Half fill the tall glass with the salt water.
- Tip it to one side and carefully pour the fresh water down the side of the glass.
- Stand the glass upright and you should see two distinct layers in the water.
How does it work?
Research: salty and fresh water
density
Source: Catalyst magazine http://www.catalyststudent.org.uk/
