Sandeep K.

Photosynthesis is a vital process in nature that converts light energy into chemical energy, providing the foundation for life on Earth. The significance of photosynthesis includes:

1. **Oxygen Production:** Photosynthesis is the primary source of oxygen in the atmosphere. Plants, algae, and some bacteria release oxygen as a byproduct during this process, which is essential for the respiration of most living organisms.

2. **Carbon Dioxide Reduction:** Photosynthesis plays a crucial role in reducing atmospheric carbon dioxide levels. During the process, carbon dioxide is taken in, and carbon is incorporated into organic molecules, aiding in the regulation of Earth's climate.

3. **Energy Storage:** Photosynthesis transforms light energy into chemical energy stored in glucose and other carbohydrates. This energy becomes the basis for the food chain, providing sustenance for plants, herbivores, and carnivores.

The balanced chemical equation for photosynthesis is:

\[ 6\text{CO}_2 + 6\text{H}_2\text{O} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \]

This equation represents the overall process where carbon dioxide and water, in the presence of light energy and chlorophyll, produce glucose and oxygen.

Assertion (A) is true, and Reason (R) is the correct explanation.

The given chemical equation \(3\text{Fe} + 4\text{H}_2\text{O} \rightarrow \text{Fe}_3\text{O}_4 + 4\text{H}_2\) is balanced, and it adheres to the law of conservation of mass, which states that the total mass of reactants must be equal to the total mass of products in a chemical reaction.