Objective: The four stages of water cycle are evaporation, condensation, precipitation and collection. It is a continuous cycle. For children in elementary classes it is very difficult to remember these abstract terms. This lesson focuses on how to teach the water cycle using simple experiments.
- Two glass bowls
- Small glass tumbler
- Water
- Paper weight
- Transparent Plastic sheet
- Sticky Tap
Procedure:
Ask your students the following questions:
- What is rain?.
- How does water reach the atmosphere?.
- How does mist disappear in the morning?.
- Direct them to watch the following experiment. Take one glass bowl and fill it with water. Mark the position of water level. Place it in open area.
- Now take the other bowl and place it too in an open area. Keep the small tumbler inside the larger one. Pour some water into the smaller one. Cover the large bowl with transparent plastic sheet and seal it using sticky tape. Place the paper weight at the center of the plastic sheet so that the depression formed, will cause the water precipitating on the plastic sheet directly to the small tumbler.
- Instruct the students to check and mark the water level in each bowl daily.
Analysis and conclusion:
Children will notice that water level decreases in the first bowl whereas it is at more or less same level in other bowl. They will understand that due to the heat from the Sun, the water in the first bowl decreases. While in the case of other bowl, even though the water gets vaporised, it is condensed on touching the plastic sheet. Thus it precipitated and is collected. They will understand the water cycle. Now let them find an answer to the previous questions.
