Science, Earth and Space Science

Grade 3- 5

Objective

Students will learn about the part the ocean plays in the hydrologic or water cycle.

Directions

Setting the Stage
Go outside and find a puddle. Mark around its edges with chalk or rocks. Observe the water over the next two days. How long does it take for the water to evaporate? What effect does sunshine or shade have on the process?
Procedure

1. Evaporation--how water gets into the air to form clouds
   1. With the wet sponge or wet towel, draw a large O for ocean on the chalkboard. Watch as it disappears. Where did it go?
   2. Repeat the procedure. This time try to make the O on the chalkboard disappear faster. See what effect fanning it with a towel (to represent wind) or heating it with a lamp (to imitate the sun's heat) might make.
   3. Record your observations on the data-capture sheet.
2. Condensation--how water changes form a vapor to a liquid
   1. About 30 minutes before this exercise, put the lid in the freezer.
   2. Place the dish on the hot plate and turn the setting on high.
   3. When the dish is warm, leave it on the hot plate, but turn off the heat.
   4. Take the lid from the freezer and put it on the dish. Observe what happens next.
   5. Record your observations on the data-capture sheet.

Extension
Complete the story of the hydrologic cycle. After water has evaporated from the ocean, clouds form. As the droplets become heavier and cool down, they fall to the earth as rain. This water collects in rivers which flow back into the ocean..
Closure
In their ocean journals, have the students write a story about the journey of a water drop as it goes through the water cycle.

Resources

• wet sponge or wet towel
• access to a freezer
• chalkboard
• hot plate
• heat-resistant dish with lid
• data-capture sheet (see link below)