Lesson Summary Students measure equal amounts of water into four containers of different shapes. The surface area of the water in each container is different. After 4 days, students measure and compare the amount of water remaining in each container. Teacher Background Evaporation is the process by which liquid water turns into water vapor, a gas. The rate of evaporation depends on four conditions: humidity, temperature, surface area exposed to the air, and air movement over the surface. The surface area of a volume of water affects the rate of evaporation. Set-up/Management Tips This part will take two sessions of 25-30 minutes, 4 days apart. Be sure to run enough regular-sized copies of the “Surface Area Chart,” one for each group. You will need a sunny or warm place for storing trays that is accessible to students. The evaporation may take between 2-4 days, or whenever the water in the flat lid is almost completely evaporated. Literacy Support Books Available Through VAST Mediagraphies (see Literacy Links) Science Stories Read “Evaporation and Condensation.” Scientific Vocabulary The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: surface area