What is the spin-only magnetic moment value (BM) of a divalent metal ion with atomic number 25 ,
Question:

What is the spin-only magnetic moment value (BM) of a divalent metal ion with atomic number 25 , in it’s aqueous solution?

1. $5.92$

2. 5

3. zero

4. $5.26$

Correct Option: 1

Solution:

Electronic configuration of divalent metal ion having atomic number 25 is

Total number of unpaired electrons $=5$

$\mu($ Magnetic moment $)=\sqrt{\mathrm{n}(\mathrm{n}+2)} \mathrm{BM}$

where $\mathrm{n}=$ number of unpaired $\mathrm{e}^{-}$

$\therefore \mu=\sqrt{5(5+2)}=\sqrt{35} \mathrm{BM}=5.92 \mathrm{BM}$