This investigation is about the effect of dish soap

This investigation is about the effect of dish soap (ml) on food colouring and milk by measuring the time taken (s) for it to reach the edge of the bowl. What causes the food colouring to spread away from the centre of the milk in the bowl? Liquids contain surface tension, surface tension is present in the top layer of the liquid, and creates an elastic surface on top of the liquid. Milk is mostly made up of water but contains fat, vitamins and protein. The protein and fat in the milk are very sensitive therefore when the dish soap is added, it creates a reaction. This is because