Answer:
The leaf discs only float in bicarbonate solution and in the light environment.
Step-by-step explanation:
The bicarbonate dissolves in water to produce a source of inorganic CO2 in the reaction:
NaHCO3 + H2O → H2CO3 + OH- + Na+
Then, the HCO3- undergoes fixation through several complex steps in order to form a carbohydrate or sugar. These store the converted solar energy in their bonds as chemical energy to be used in metabolism.
Photosynthesis is a chemical process, essential to plant and other primary producers producing energy. Energy in the form of glucose molecules is derived from solar or light energy, water, and inorganic carbon dioxide, while it releases oxygen (from the light reaction). The leaf discs float as O2 gas is produced, making them buoyant.
6CO2 + 6H20 + (energy) → C6H12O6 + 6O2
Carbon dioxide + water + energy= glucose + oxygen