Simple Science Experiment with Milk

 This is such a fun science project to do with kids. We have done this several times and they love it. They even ran to get a neighbor kid to come over and watch too. You can see the video of how it works below, but all you need is whole milk, dish soap (not a natural kind) and food coloring. As an adult who never did it before, I thought this was really cool.

There are a couple of things happening here, the first is differences in density of liquids. Food coloring is less dense than the whole milk, so it just sits on top. The second thing is surface tension which both water and milk have, but when you apply soap it reduces the surface tension and causes the liquid particles to move.