Summer Vacay - Day 15: Surface Tension

This morning we had a little bit of rain and it was quite overcast so we did a science experiment as one of our fun summer vacation activities of the day. We learned a little bit about surface tension, or I learned about surface tension and they learned how pretty food colouring looks in milk. All we needed was enough milk to fill the bottom of a clear dish, food colouring and dish soap. As you can see we used Dawn and it seemed to work fine. It was suggested that the fattier the milk the better and we only had 2% so that's what we used but I'm interested to see what Half and Half would be like. So you fill your clear dish with milk and wait a little bit for it to warm to room temperature. Once the milk isn't fridge cold we each put a drop of each of our colours completely in its own space away from the other drops so it looked just like our picture below. Sydney then dropped one tiny drop of the liquid Dawn into the middle of the dish and we sat back and watched.

In the beginning, because the milk is quite a bit denser then the food colouring drops, the drops just nestled into their spots on the surface. As soon as the Dawn is placed into the milk the surface tension starts to change and the colouring sunk a little bit and started swirling around in the milk. After a little bit of time different colours would pop up in a different area and mix with a different colour. It started to look really cool and then everything stopped so we added an extra drop of Dawn and the magic started happening again. After the kids got bored with it they started sticking their fingers in it and because of the crazy surface tension, when they would flick a bit of the liquid up it would ball on the surface and roll before absorbing back into the milk/Dawn/colouring solution. It was really the coolest part of the whole thing! I'm not too sure if the kids learned anything about surface tension but it sure looked pretty and they always love getting their fingers a little messy so I'd have to say it was a success!