Follow these instructions and then answer the questions below:
- 1 tablespoon of liquid laundry detergent.
- food colouring (at least 2 different colours)
- full fat milk
1. Pour the milk onto the plate until it covers the whole surface but does not spill over (leave some room.)
2. Drop on the food colouring randomly. Do not mix.
3. Roll the flannel tightly (if you can, fix it with an elastic band) and dip the end into the laundry the detergent until it covers about half a centimetre at the end.
4, Before the next step, predict what might happen if you place the flannel, detergent side down, into the centre of the plate.
5. Place the flannel, detergent side down, into the centre of the plate.
a. Why did the food colouring not mix with the milk when it is dropped in?
b. Why is it important to dip the flannel in the detergent and then place it on the plate rather than pouring the detergent straight in. If you want do the experiment like this and see what the difference is..
c. What happens to the food colouring and milk when the flannel is placed on the plate?
d. Why do you need to use a shallow object like a plate for this experiment rather than a deep one, like a bowl?