One of the earliest experiments on photosynthesis was done in 1770 by Joseph Priestley.He demonstrated that

Options

A. sunlight is the energy source
B. water is required
C. plants and animals "restore" the air for each other
D. chlorophyll captures light energy

Answer

**Step-by-Step Solution:**

1. **Identify the Experiment**: Joseph Priestley's experiment was conducted in 1770 to study the process of photosynthesis.

2. **Setup of the Experiment**: Priestley used a mint plant placed in a closed container. This setup was crucial for observing the effects of gas exchange.

3. **Lighting the Candle**: A candle was lit inside the closed container. The candle flame required oxygen to burn, which was present in the container initially.

4. **Oxygen Consumption**: As the candle burned, it consumed the oxygen in the container. Eventually, the oxygen was depleted, and the candle extinguished.

5. **Formation of Carbon Dioxide**: When the candle burned, it produced carbon dioxide as a byproduct. This gas accumulated in the container after the oxygen was consumed.

6. **Role of the Mint Plant**: The mint plant, being a photosynthetic organism, was able to utilize the carbon dioxide present in the container.

7. **Production of Oxygen**: Over time, the plant converted the carbon dioxide back into oxygen through the process of photosynthesis.

8. **Re-lighting the Candle**: After a period of 27 days, Priestley was able to re-light the candle in the container. This demonstrated that the plant had produced oxygen, which was necessary for combustion.

9. **Conclusion**: Priestley’s experiment provided early evidence that plants can produce oxygen from carbon dioxide, highlighting the importance of photosynthesis in maintaining atmospheric oxygen levels.

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