Reading about science is not the same as “doing” science. Hand-son activities are great ways for younger students to grasp science concepts.
Learning about the water cycle is one of those areas where doing the science helps to solidify their understanding. With this activity, your kids will better grasp how the water cycle works.
Water cycle in a bag activity
You will need the following materials:
- A medium-sized plastic bag
- Blue food coloring
- A permanent marker
- Packing tape
- A window that gets lots of exposure to the sun or a hairdryer
Once you have all the materials, here’s what you need to do:
Draw the water cycle on the bag, making sure to include a body of water (lake or ocean), land with a rising hill or mountain, clouds and the sun.
Once completed, add about 2 inches of water to the bag and add a couple of drops of the blue food coloring to the water.
Now, seal the bag. Make sure that it is completely sealed for this experiment to work.
Once sealed, use the packing tape to tape the bag to a window. Pick a south-facing window that you know will get lots of exposure to the sun. Alternatively, you can use a hairdryer on low speed to conduct this experiment a bit faster.
After several hours of exposure to the sunlight, you’ll see the humidity levels in the bag rise. You’ll see drops of water on the inside of the bag above the water level. Some droplets will trickle down the inside of the bag. This serves to explain the three basic processes of the water cycle:
Evaporation: as the bag warms some of the water turns into water vapor and evaporates.
Condensation: as the humidity rises, the air in the bag gets saturated and some of the water condenses back into drops of water.
Precipitation: the drops of water collect along the sides of the plastic bag and roll down its sides into the pool of water at the bottom (collection).
Grade 2 Water Cycle Worksheets
In our grade 2 science section, we’ve created a couple of worksheets for students to practice their understanding of the water cycle.