Question

The sum of electronic spins of all electrons present in the $3d^7$ configuration is:

• A. $+\frac{3}{2}$
• B. $+\frac{5}{2}$
• C. $+\frac{7}{2}$
• D. $+\frac{9}{2}$

Answer 1

The correct option is A $+\frac{3}{2}$

The electronic representation of $3d^7$ configuration is shown in the figure given above.
Sum of spin = $5\times \frac{1}{2}+2\times \frac{-1}{2}$$=\frac{5}{2}-1=\frac{3}{2}$