Give students an overview of evaporation and condensation. An overview serves as a good introduction to the topic and will help you understand areas that are causing confusion with your class. Explain to your students that evaporation is when liquid water turns into water vapor -- a gas -- as a result of increasing temperature or reduced pressure, while condensation is when water vapor turns into liquid water due to decreasing temperature or increased pressure.
Both evaporation and condensation are part of the water cycle, so incorporate both into an activity addressing the cycle as a whole. One interactive activity idea is having students draw the water cycle as it pertains to their lives. Have students draw their houses and families and include the steps in the water cycle, such as evaporation, condensation and precipitation, as it applies to local bodies of water and landmarks. Additionally, create a word search or word jumble for terms related to evaporation, condensation and the water cycle, or share impressive water trivia facts -- 70 percent of earth's water is in glaciers -- with your students. Such facts work well as a fun quiz game.
One way to illustrate the idea that evaporation is a product of the surrounding pressure and temperature is by placing two cups of water on a table, one covered and one uncovered. The uncovered one will have lower surrounding pressure and higher temperature from the outside air, so it will evaporate, while the covered water will not.
A classic case of condensation with which your students may already be familiar is the dew on grass, so if you have a morning class, take your students out to investigate this occurrence. Another way to illustrate the concept of condensation is by placing a cool glass and a warm glass on a table. The cool glass will cause condensation because surrounding air will slow down due to the reduced temperature, while air around the warm glass will continue to move at the same pace.