Final answer:
The student observed the process of photosynthesis, during which plants convert carbon dioxide and water into glucose and oxygen using sunlight energy. The correct answer to which reactants were needed is option a) 15 grams of carbon dioxide and water were needed to produce 15 grams of glucose and oxygen.
Step-by-step explanation:
Observing Photosynthesis and Cellular Respiration
When a student observes the production of 15 grams of glucose and oxygen in plants, they are witnessing the process of photosynthesis. Photosynthesis is the process through which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. The chemical equation for photosynthesis can be represented as 6CO₂ + 6H₂O + Energy → C₆H₌₆ + 6O₂, which indicates that carbon dioxide and water are the reactants and glucose and oxygen are the products of this biochemical reaction. Therefore, for the student to observe the creation of 15 g of glucose and oxygen, a similar amount of carbon dioxide and water was required initially. This addresses the part of the question concerning how much of the reactants were needed. It is important to note that the actual mass of reactants might not precisely equal the mass of the products due to the biochemical complexities and efficiencies involved in the photosynthesis process.
The option c) The student observed photosynthesis, and 15 grams of carbon dioxide and sunlight were needed is not completely accurate, as it fails to mention water as a necessary reactant. The correct option that reflects both observation and necessary reactants is a) The student observed photosynthesis, and 15 grams of carbon dioxide and water were needed. This option correctly identifies the observed process as photosynthesis and the reactants as carbon dioxide and water.
Conclusion
In conclusion, the student observed photosynthesis, and to produce the 15 grams of glucose and oxygen, the plant would have needed approximately 15 grams of carbon dioxide and water, provided sufficient sunlight was also available to drive the reaction. The correct option for this scenario is a) The student observed photosynthesis, and 15 grams of carbon dioxide and water were needed.