Penny Lab

For this lab, the materials required were a penny, a cup of water, and a water dropper. The way the lab was performed was that the water dropper was filled with water. One drop at a time was dropped onto the penny. This was done because our class wanted to see how many drops of water could be dropped onto a penny before the water overflowed off of it.

I thought that the penny couldn't hold more than maybe 3 or 4 drops of water. I figured the water would just slide right off the penny.

The actual outcome was very different from my prediction. The penny that I applied the drops of water to held 17 drops of water before it overflowed.

The explanation for this is that the property of water called adhesion was in effect. Adhesion means that the molecules of water clump together. As I applied the drops onto the penny, the water clumped together more and more with each drop, forming a large drop of water ontop of the penny. The drop of course became too big after the 17th drop and flowed off the penny.