The source of oxygen evolved during photosynthesis is

Options

A. `H_(2)S`
B. `H_(2)O`
C. `CO_(2)`
D. `HCO_(3)`

Answer

To answer the question regarding the source of oxygen evolved during photosynthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, producing glucose and oxygen as byproducts.

2. **General Equation of Photosynthesis**:
- The overall reaction can be summarized as:
\[ 6CO_2 + 6H_2O \xrightarrow{\text{light, chlorophyll}} C_6H_{12}O_6 + 6O_2 \]
- Here, carbon dioxide (CO2) and water (H2O) are the raw materials, while glucose (C6H12O6) and oxygen (O2) are the products.

3. **Identifying the Source of Oxygen**:
- From the equation, we see that oxygen is produced alongside glucose. The question asks for the source of this oxygen.
- The two raw materials involved are CO2 and H2O.

4. **Differentiating Between CO2 and H2O**:
- During the light reactions of photosynthesis, water (H2O) undergoes photolysis, which is the splitting of water molecules.
- This process releases oxygen (O2) as a byproduct.

5. **Conclusion**:
- Therefore, the source of the oxygen evolved during photosynthesis is **H2O (water)**.

### Final Answer:
The source of oxygen evolved during photosynthesis is **H2O (water)**.

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