When you look at a drop of water it makes a dome shape rather than run flat on a table. This is caused by water surface tension. Surface tension is created when the water molecules hold on tightly to each other. The molecules at the surface hold on to each other even more because there is no water molecule above them to grab on to. This tension keeps the drop of water together in the dome shape.
You may have seen drops of water on leaves and observed the domes of water they formed, but have you ever thought how much water could fit on before it all falls off? This week we first investigated the shapes and nature of drops of water and how we can break the water tension. We then came back together to share our observations. Part of being a scientist is to make predictions and then conduct an experiment to see if our predictions are correct. Based on our observations we all made a prediction of how many drops of water we could fit on a 10 cent coin. Our predictions ranged from 5-10 drops.
Through multiple testings and changing the variables, such as turning the coin over, mean that we were confident in our observations. The most drops some of us put on the coin was 32! A lot more than any of us predicted.