Tuesday, February 15, 2011
Cut a piece of paper to fit in the pan. Lay the paper on the water's surface.
Pick up the paper and lay flat to dry.
Now, sprinkle the water's surface with herbs and spices once again.
What differences do you notice between the two trials? Why did the soap cause such a difference?
The soap reduces water's surface tension. The herbs and spices, which are normally held on top of the water by the surface tension, now fall into the water. As a result, the paper, which only touches the surface of the water, doesn't collect very much.