The best way for children to observe a plant carry out photosynthesis first hand is to give the plant what it needs (sunlight, carbon dioxide, and water), and then watch it happen!
If we use aquatic plants, we can watch the oxygen bubbles escape the plants in this simple experiment.
Materials:
- large test tubes
- mason jars or glass beakers
- strong lamp
- live aquatic plants (from the fish section of the pet store)
- baking soda
Procedure:
- In a sink or large bin of water, place the aquatic plant inside the test tube, inverted, inside the jar. Do this so that there is no air in the test tube at all.
- Place a pinch of baking soda into the jar (to add CO2).
- Place the jar under a strong lamp. Wait a minute…
- Watch as the tiny oxygen bubbles start to whiz from the plant leaf up to the top of the test tube. (They are small and fast, so use good observation skills!)
Go Further:
- Make this into an experiment and compare how many bubbles come out of the plant when it is under the light vs. how many bubbles come out of the plant when it isn’t under a direct light. Don’t forget to do many repetitions and discuss variables!
