Crazy Colours. A spectacular effect with the minimum or resources and effort! Children love this experiment but do get them to ‘predict’ what they think will happen before adding the soap. Then at the end ask them to think ‘why’ it happened. There is a video giving a simple explanation for them to watch on my channel. It’s called ‘Crazy Colours’ and it is in the FUN SCIENCE playlist. The Jumblefun Channel
I used UHT semi-skimmed milk. A further experiment could be to see if anything different happens when you use full fat or skimmed milk. For a rainbow effect use red, blue and yellow. The soap can be applied by a brush as shown in the video or by finger or cotton wool bud.
Why does it happen?
Although milk is mainly water it does contain lots of other things like vitamins and protein and fat.
Fats and protein are very sensitive to changes in the milk. When soap is added it sends the fat molecules crazy and they all start to twist and turn. During these acrobatics the colour molecules get pushed around so creating the crazy patterns.
Watch the very short video demo below. Have fun!