Isotope of oxygen used in studying photolysis is

Options

A. `.^(16)O`
B. `.^(15)O`
C. `.^(17)O`
D. `.^(18)O`

Answer

**Step-by-Step Solution:**

1. **Understanding Photolysis**: Photolysis refers to the process of splitting water molecules (H2O) into protons (H+), electrons (e-), and oxygen (O2) using light energy during photosynthesis.

2. **Identifying the Isotope**: To study the source of oxygen released during photosynthesis, scientists needed to trace the origin of the oxygen atoms. They used a specific isotope of oxygen for this purpose.

3. **Using Oxygen-18 (O-18)**: The isotope of oxygen that was used in the study of photolysis is Oxygen-18 (O-18). This isotope is a heavier form of oxygen, which can be tracked in chemical reactions.

4. **Experimental Setup**: In the experiment, carbon dioxide (CO2) and water (H2O) were used. The water used in this experiment contained the O-18 isotope, allowing researchers to trace where the oxygen released during photosynthesis originated.

5. **Observation and Conclusion**: After conducting the experiment, it was observed that the oxygen released during photosynthesis was labeled with the O-18 isotope. This indicated that the oxygen produced came from the water molecules (H2O) and not from carbon dioxide (CO2). This conclusion helped clarify the role of water in the photosynthetic process.

**Final Answer**: The isotope of oxygen used in studying photolysis is Oxygen-18 (O-18).

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