What You Need:
- Small soft drink bottle
- Food colouring
- Cooking oil - 2 tablespoons
- Dishwashing liquid
- Add a few drops of food colouring to the water.
- ¨Pour about 2 tablespoons of the coloured water along with the 2 tablespoons of cooking oil into the small soft drink bottle.
- Screw the lid on tight and shake the bottle as hard as you can.
- ¸Put the bottle back down and have a look. It may have seemed as though the liquids were mixing together but the oil will float back to the top
While water often mixes with other liquids, it does not form a solution with oil. This is because water molecules are strongly attracted to each other and so are the oil molecules. This means that the water and oil molecules are so attracted to their own molecules that they just don't mix together. If you want to bring oil and water together, you need to try adding some dishwashing liquid or detergent to it. Detergent is attracted to both water and oil and this helps them join together and form something called an emulsion. This is why detergent helps takes the oil and grime off utensils when you are washing dishes.