You Light Up My Life
Purpose: To demonstrate the production of oxygen by green plants.
Materials: Elodea, two funnels, two test tubes, two containers (large enough to hold funnels), matches, wood sliver, baking soda, 1/4 teaspoon, washers
Procedure:
Put two springs of Elodea in each container and add enough water to cover them as shown.
Stir in 1/4 teaspoon of baking soda to provide a source of carbon dioxide.
Cover the plants with funnels. Rest the funnels on washers to admit air freely.
Place a test tube over the funnel.
Tilt the funnel and tube to till them up with water and to remove air. Replace upright.
Place one container in bright sunlight.
Place one container in a poorly lit area.
After a few days compare the plants. Record any differences.
Teacher (Test for Oxygen)
When the test tube is over 1/2 filled with oxygen, remove from the funnel.
Light the wood sliver and blow out the flame.
Place the glowing sliver quickly into the test tube.
Questions:
What is the difference between the test tubes?
Why do you think this difference happens?
What happens to the sliver when it is placed in the test tube and why?
How is this experiment part of the carbon dioxide-oxygen cycle?
Return to Spaceship Earth