Tie Dyed Milk Experiment – Surface Tension By: Yoli Rosendo and Raven Burns My name is Yoli Rosendo is Raven Burns. Today we will be doing an experiment on surface tension with you. So what is surface tension? Surface tension is a property of the surface of a liquid that allows it to resist an external force. We are going to demonstrate how surface tension works using: dish soap, food dye, and milk (it is best to use half and half or whole milk). You will also need a plate. So let’s start by pouring the milk into the dish. Make sure that you have enough room in the plate so that you have a shallow pool about 1 cm deep. So what is happening? When we first put the food coloring it just sat on the surface of the milk . The milk is denser than the food coloring which allows the food coloring to just float on the surface. The soap reduces the surface tension of the milk by dissolving the fat molecules. Then take your food dye and spread it out however you want. We are going to use different colors and spread them out evenly so that you can see the full effect the soap will have with each color. Take the dish soap and pour one drop in the middle of the dish. Make sure you do not drop any soap directly onto the food coloring.