This week in STEM club we were investigating how many drops of water can a penny hold? You will be amazed by the answer.
Simple questions to get your junior scientist thinking!
- How many drops of fit do you think will fit on a penny? (PREDICTION)
- What is happening when one drop of water meets another drop? (OBSERVATION)
- Which coin held the most water? (EXPLANATION)
We learnt that tension and cohesion is the reason you can get so many drops of water on a penny. Cohesion is the “stickiness” of like molecules to one another. Water molecules love to stick together! Surface tension is the result of all the water molecules sticking together.
Once the water has reached the edge of the penny, a dome shape begins to form. This is due to the surface tension forming a shape that has the least amount of surface area possible (like bubbles)!