Simulated acid rain, a dilute sulfuric acid solution, needs to be prepared for this demonstration. After a condensed lecture on acid rain, you will apply the solution to a sample of granite and a sample of limestone. Your young scientists will create a data table in which to record the pH of the acid rain both before and after passing through the stone samples. The lesson is not exciting, but it effectively shows how limestone can have a buffering effect for the plants and animals.