Question

If the atomic number of an element is $26$, the magnetic moment (in Bohr magneton) shown by its ion in $+2$ oxidation state will be:

• A. $1.75$
• B. $2.86$
• C. $3.87$
• D. $4.90$

Answer 1

The correct option is D $4.90$

It is given that if an element has atomic number as $26$ and its ion is in $+2$ oxidation state, then its electronic configuration will be $d^6$ with $4$ unpaired electrons.

The formula for the magnetic moment is $\sqrt{n(n+2)}$, where $n$ is the number of unpaired electrons.

Hence, its magnetic moment is $\sqrt{4(4+2)}=4.90$ Bohr magneton

Option D is correct.