Proving the Water Cycle

Sixth graders used the outdoor classroom to help prove how the water cycle works.  A small stone was placed in the bottom of a baggie.  The baggie was tied around the leaves of a green plant with a twist tie.  One day later the students checked the baggies and found that droplets of water had transpired through the leaves of the plant and collected in the bottom of the baggie.

A second observation was made in the classroom.  Students filled a clear, plastic cup with 200ml of water and added 10ml of salt to the cup.  After the salt had dissolved, students tasted the salty water.
A clear plastic wrap was placed over the top of the cup and the cup was put under the grow light.  The light was moved to within 15cm of the cups.  After 24 hours, the students noticed that the water had formed condensation on the bottom of the plastic wrap.  They tasted these droplets of water and found that they no longer tasted like salt.

Students concluded that water is purified when it evaporates and when it transpires through the leaves of plants that are going through the process of photosynthesis.  Sixth graders are working on finding answers to the essential question - "How does a system of living and non-living things operate to meet the needs of the organisms in an ecosystem?"  Clean water is one of the abiotic factors that is increasingly important in the world.