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

Explanation

To determine the valency of iron based on its spin-only magnetic moment of 5.91 Bohr Magneton (BM), we can follow these steps:

### Step 1: Understand the Formula for Spin-Only Magnetic Moment
The spin-only magnetic moment (µ) is given by the formula:
\[ \mu = \sqrt{n(n + 2)} \]
where \( n \) is the number of unpaired electrons.

### Step 2: Set Up the Equation
...