USING SCIENCE SKILLS

Question

A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by each sprig of the water plant. Shown here is the graph of the data for the beaker she placed in the light.
Experiment1bubbles.png

If the student tested the air bubbles, what would she find they are made of

Answer 1

The bubbles produced by the water plant during photosynthesis are primarily composed of oxygen gas (\( O_2 \)). During the process of photosynthesis, plants take in carbon dioxide (\( CO_2 \)) from the air and water (\( H_2O \)) from the soil, and using light energy (in this case from the fluorescent lamp), they convert these into glucose (\( C_6H_{12}O_6 \)) and oxygen. The oxygen is released as a byproduct, which is what the student counted as bubbles.

Therefore, if the student tested the air bubbles, she would find that they are predominantly made of oxygen gas.