Question

Find the magnetic moment of a divalent ion in aqueous solution if its atomic number is $25$:

• A. $6.9\text{B.M}$
• B. $5.9\text{B.M}$
  
• C. $4.9\text{B.M}$
  
• D. $3.9\text{B.M}$
  

Answer 1

The correct option is B $5.9\text{B.M}$


Magnetic Moment $\left(\mu \right)=\sqrt{n(n+2)}$
Where $n=$ number of unpaired electrons.
Atomic Number $\left(25\right)=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}4s^2$
$\text{n}=5$
Q It is a divalent so $4{\text{s}}^0$ in $M^{+2}\text{n}=5$
$\therefore \mu =\sqrt{5(5+2)}=\sqrt{5\times 7}=\sqrt{35}$
$=5.916\text{BM}=5.9\text{B.M}$