You may well drink the white stuff every day but until now you probably never knew you could do an incredible science experiment with normal, everyday milk. Well, you do now! – So let’s get started!
What do I need?
- A plate or bowl
- Washing up liquid
- Half a glass of milk
- Food colouring
How do I do it?
STEP1 - Pour milk into the bowl or plate until the surface is well covered
STEP2 - Add several spots of food colouring onto the milk (You don’t have to make a face like we did!)
STEP3 - Cover the end of your finger with washing up liquid (use a pen or pencil if you don’t fancy getting messy)
STEP4 - Dip your finger into the middle of the milk – Watch in amazement as the colours go flying off all over the place!
What’s going on?
This one is all to do with something called surface tension. The force between the molecules on the surface of the milk.
Adding the washing up liquid reduces the surface tension of the milk. The rest of the milk still has the same surface tension that it always did and so pulls the milk outwards taking the food colouring with it! Cool, huh!
More Fun Please! - Experiment like a real scientist!
- Is the type of milk important? Full fat? Skimmed?
- Which type of soap works best?