Tell the children that they are going to learn about a process called condensation. Show the children four clear, empty, clean glasses. Place one empty glass in a refrigerator or freezer. Fill one glass in front of the children with cold water. Fill another glass in front of the children with the colored drink. Leave the last glass empty; this serves as the "control" glass. Even with small children, it is helpful to start them using controls in their science experiments. Leave these glasses alone for 10 to 15 minutes to allow the experiment time to take place.
Read the "To the Mountains and Back: Drippy the Raindrop" online story to children in middle school or younger (see Additional Resources for the link). Give older children the option to read the story; most children will want to read it because they like online story books.
Explain the definition of condensation to the children. Write the word down so they can see how it is spelled. Pronounce condensation as you run your hand, finger, pointer or laser beam pointer underneath the syllables to emphasize how to pronounce words properly. Share the definition. Ask children for examples of condensation. Discuss real-world applications and show pictures and illustrations if available.
Use an online dictionary that pronounces condensation for the children. Using this technology will pique their interest more (link for Yahoo! Kids Dictionary with pronunciation for condensation is provided under Additional Resources).
Show children pictures of condensation. Colorful images will capture their attention, and they will be more likely to commit the definition and condensation lesson to long-term memory. (An example of an interesting image of condensation on a plant is in the links under Additional Resources.)
Put all the experiment glasses on a table in front of the children, each glass about 12 inches apart so the results are not compromised by a cool glass being too close to a room temperature glass. Supply each child with a piece of paper to take notes or a worksheet with glasses already drawn in so they can color in the steps of the experiment and results. Older children can also be asked to supply a thesis, materials, research steps, etc. Now ask questions of the children and explain the findings.
Ask children how they think the water got on the outside of the glass with cool water. Smaller children might answer "condensation" or "from the inside of the glass" or "that the water crawled out of the glass onto the other side."
Show children the glass with the cool colored drink on the outside. Explain that if the liquid "transferred" or "crawled out" then it would not be clear.
Show children the empty cool glass from the refrigerator or freezer. Remind the children that this glass started with no liquid inside and also had condensation, this will also illustrate that the water does not "leak through" or "crawl out."
Now explain to the children the process of condensation in terms they understand, illustrating the explanation using the glasses including the control glass (this one has not changed). Write any big words, such as molecules, on the board or provided on their paper with a definition. For very small children, under third grade, writing the terms water, glass, H20, cool, warm, temperature, control, experiment and other related terms will be appropriate and help them to learn to spell science words.
Wrap up the lesson with a video that illustrates condensation as a review. Eureka! Episode 18 - Evaporation and Condensation (link provided under Additional Resources) is a good example of a video that can be used to wrap up the condensation lesson.
The wrap-up video can be more complicated than the introduction video or story because the children will have a much greater understanding of condensation after the experiment. Even if a video has some words and definitions that are above the age or grade level, exposure is still excellent because these new scientific terms, illustrations and ideas can soak into the children's memory.