The largest reservoir of nitrogen on earth is--

Options

A. The soil
B. The air
C. The oceans
D. Granite rocks

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the largest reservoir of nitrogen on Earth. This means we need to identify where the most nitrogen is stored.

2. **Evaluating the Options**:
- **Option 1: Soil**: While soil does contain nitrogen, it is not the largest reservoir.
- **Option 2: Air**: The atmosphere is composed of various gases, and nitrogen is a major component.
- **Option 3: Ocean**: The ocean does contain some nitrogen, but it is not the largest reservoir.
- **Option 4: Granite Rock**: Granite rock does not contain significant amounts of nitrogen.

3. **Analyzing the Air**: The atmosphere is made up of approximately 78% nitrogen. This is a significant percentage compared to other sources of nitrogen.

4. **Conclusion**: Based on the evaluation of the options and the analysis of nitrogen content, the largest reservoir of nitrogen on Earth is the air.

5. **Final Answer**: The largest reservoir of nitrogen on Earth is the air.

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