One of the easiest ways to teach about the sun’s power is to explore how the heat from the sun can affect water. In doing some of these activities below, your kids will begin to understand the basics of evaporation and condensation.
Background to Show Evaporation
First, use a clear Pyrex measuring cup to provide some background and create some intrigue. Have your children fill the measuring cup to the one cup line. This is great practice for young kids! Your children can pick a special spot outside to keep the measuring cup for 24 hours. When time is up, your kids will be surprised to see that the water level has decreased after a day of sitting outside!
My daughters were shocked to see we went from 1 cup to 3/4 cup! They wanted to know how that happened! (It came off like a magic trick!) After they take some guesses, you can explain to your kids that little tiny droplets (molecules) of water, separated from the rest of the water in the cup and rose into the sky (as a vapor). This water vapor helps create clouds high in the atmosphere. To show this directly, you can heat up a tea kettle or covered pot of water. When it begins to boil, quickly uncover it. Your kids will be able to see the cloud of steam (water vapor). The steam looks cloudy but contains teeny-tiny water droplets. You can connect this to how the water outside evaporated from the cup.
3 Easy Ways to Show the Sun’s Power on Water
1. Have your kids place a few teaspoons of water in a Ziploc bag and seal the bag. Hang it outside on the window or on the slider door for the day where the sun can provide it some heat. Your kids will love checking on the progress to see the cloudiness appear in the baggie. In the picture below, you can see the cloudiness on the sides of the baggie. This is condensation.
2. Your children can place water in clear plastic or glass cup. Help them cover the cup tightly with plastic wrap and choose a sunny place outside. Throughout the day, your kids will be able to observe water condensation on the plastic wrap. The water droplets on the top of the plastic wrap have been formed by tiny water droplets leaving the original water in the bottom of the cup.
3. Place some water in a plastic deli or take-out container and put the lid on top. Throughout the day, your kids will be able to see the water condensation on the top of the plastic lid. It starts cloudy, but the more time it sits, the larger the droplets of condensation on the lid.
Why Does this work?
When the sun heats the water, tiny water particles separate from the main body of water creating an invisible vapor (evaporation). The vapor inside these 3 experiments gets trapped because it can’t escape the container (serving as the atmosphere). Tiny vaporous water droplets join to form a liquid (condensation).
This activities lends itself easily to a segue into the water cycle and cloud formation. Check out the USGS for a fun printable placemat for kids illustrating the Water Cycle.
Check out this Weather Blog Hop for some fun weather-related ideas.
Join us tomorrow for a continuation of Solar Week here on No Doubt Learning where we’ll focus on some easy activities to see how the affect sun’s heat has on color and temperature!