Why Nitrogen is not considered a true mineral?

Explanation

### Step-by-Step Text Solution:

1. **Definition of Minerals**: In the context of plant nutrition, minerals are typically defined as inorganic substances that are absorbed by plants from the soil in their ionic forms. They are essential for various physiological functions.

2. **Nitrogen's Presence**: Nitrogen is abundant in the atmosphere, making up about 78% of the air we breathe. However, it exists primarily in its diatomic molecular form (N₂), which is inert and not directly usable by plants.

3. **Inert Nature of Atmospheric Nitrogen**: The nitrogen gas in the atmosphere is chemically stable and does not readily react with other substances. This inertness means that plants cannot directly absorb nitrogen from the atmosphere in its gaseous form.

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