Surface Tension

Question:

What is the trick behind floating a paper clip on water?

Answer:

There is no trick. The diagram shows the paper clip on a small piece of paper. I used a piece of paper towel. The paper helps to position the paper clip so that is sits flat on the water. The pencil in the diagram is pushing the edge of the paper beneath the water which causes the paper to sink.

While it may look like a magic trick, the paper clip continues to float on the surface of the water because of the surface tension of water.

Surface tension describes the attraction between the surface water molecules which causes the surface of a liquid to act like a thin skin is stretched across it. For information about the force of attraction between water molecules, see   COHESION.

Janice VanCleave’s 203 Icy, Frosty, Cool and Wild Experiments