This is one in several lessons that explore the relationship between temperature and phase changes of water. After some discussion, elementary physical scientists place wet paper toweling on a hot and a room-temperature water bag and evaluate the evaporation rate. Consider having older learners record the actual time taken for complete evaporation and then combining data with the rest of the class and creating a graph of results. Not only can this be used in a physical science setting, but also as part of your water cycle curriculum in earth science.