We did this fun experiment and you can try it at home. What you need: milk, 4 or 5 different colours of food colouring, 2 cotton buds, dishwashing liquid and a shallow plate. What you do: Pour milk onto the plate so that the bottom of the plate is covered. Put a drop of food colouring (each colour) in the centre of the milk. Give a little stir with one cotton bud. Dip the other cotton bud in dishwashing liquid. Dip the cotton bud into the milk and watch what happens. What happened: The colour moves away from the cotton bud and makes colourful swirls. How does it work? Milk is mostly water but it also contains vitamins, minerals, proteins and tiny droplets of fat. (We used full cream, blue top milk.) Fats and proteins are sensitive to changes in the milk. The colour bursts result from the chemistry of that tiny drop of dishwashing liquid on the cotton bud. Dishwashing liquid weakens the chemical bonds that hold the protein and fats in the milk. The fat molecules move away from the soap, and during all this the food colouring molecules are bumped and shoved everywhere, making it easy for us to see what is happening.
My name is Angela Jones (Mrs Jones). I have been teaching at South Hornby School for 20 years. I have taught new entrants through to Year 5. I am the leader of the Middle Syndicate team of 4 classes of Year 3 and 4 students. I love my job!