Pūtaiao - Science
We have been experimenting with water surface tension. The properties of the water and the cinnamon do not work well together, and therefore these two substances are not easily mixed. So when you put your finger in the glass, the cinnamon will form a layer between you and the water and you will not get wet. On top of the water, there is something called surface tension. It is a force that can be compared to a thin barrel of the water. That is why some insects can walk on the water surface. When you dip the liquid soap into the water, the surface tension is destroyed and the cinnamon moves away.
Watch the video below for an example;
We then tried the same experiment using pepper. We noticed that the pepper repelled faster than the cinnamon. The cinnamon would clump together quickly if we left it for longer than 10 seconds. This made the cinnamon bigger and therefore slower to repel the soapy finger.
We also noticed that sometimes the cinnamon would split into different shapes! We wonder why and how this happens?
