What will be the valency of iron if its spin-only magnetic moment is 5.91BM?

Explanation

To determine the valency of iron given its spin-only magnetic moment of 5.91 BM, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Magnetic Moment Formula**:
The spin-only magnetic moment (μ) is given by the formula:
\[
\mu = \sqrt{n(n + 2)}
...