This is an activity (located on page 4 of the PDF under Surface Area Activity) about surface area and reactivity. Learners will perform a variation on the popular soda geyser activity, using different sizes of rock material in place of candy. Students will do 3 trials for each type of rock, record the height of each resulting geyser, and average their results. This resource includes information about how researchers can use nanoparticles as catalysts and relates to linked video, DragonflyTV Nano: Surface Area.