Objectives Exploring the concept of surface tension Making and testing a hypothesis by estimating the number of water drops that can fit on a penny and testing their predictions Analyzing data by averaging and comparing figures Materials Needed Water Drop Record Sheet Pennies (one for each student) Eyedroppers Cups of water Introduction Ask students if they have ever seen a mosquito or other small bug sitting on the surface of a body of water. Explain that the surface of the water acts as “skin.” It tends to hold together because the water molecules are attracted to each other. This is called surface tension. Tell students that they are going to conduct an experiment that demonstrates how water molecules stick together to create surface tension.
