Students see how different levels of surface tension affect water's ability to move. Teams "race" water droplets down tracks made of different materials, making measurements, collecting data, making calculations, graphing results and comparing to their predictions and the properties of each surface, determining which surface exhibits the highest (or lowest) level of surface tension with water. They apply their results to make engineering recommendations for real-world applications.

At this site, the student can find out thermophysical properties of different fluids and gases.

This activity provides students with a first look at water tension and its role in the life of a water strider.

This activity provides students with a first look at water tension and its role in the life of a water strider.

This pathway provides an introduction to the structure of water and properties of water, such as hydrogen bonding, that make it essential for life. For a deeper look at this topic, we recommend the pathway The Chemical Foundation of Life from the OpenStax textbook Biology for AP® Courses.

Students conduct a simple test to determine how many drops of each of three liquids water, rubbing alcohol, vegetable oil can be placed on a penny before spilling over. Because of their different surface tensions, more water can be piled on top of a penny than either of the other two liquids. However, the main point of the activity is for students to come up with an explanation for their observations about the different amounts of liquids a penny can hold. To do this, they create hypotheses that explain their observations, and because middle school students are not likely to have prior knowledge of the property of surface tension, their hypotheses are not likely to include this idea. Then they are asked to come up with ways to test their hypotheses, although they do not need to actually conduct these tests as part of this activity.

Students are presented with the concepts of wetting and contact angle. They are also introduced to the distinction between hydrophobic and hydrophilic surfaces. Students observe how different surfaces are used to maintain visibility under different conditions.