Predict the modes of occurrence of the following three types of metals :
(a) Highly reactive (e.g `Na`)
(b) Moderately reactive (e.g `Fe`)
( c) Noble metal (e.g `Au`).

Explanation

To predict the modes of occurrence of the three types of metals: highly reactive (e.g., Na), moderately reactive (e.g., Fe), and noble metal (e.g., Au), we can analyze each type based on their reactivity and natural forms.

### Step-by-Step Solution:

1. **Highly Reactive Metals (e.g., Na)**:
- Highly reactive metals, such as sodium (Na), do not exist in their free state due to their high reactivity.
- They primarily occur in a combined state, often as salts or minerals.
- Common occurrences include:
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