Question

The total spin and magnetic moment for the atom with atomic number $7$ are:

• A. $\pm 3, \sqrt{3} BM$
• B. $\pm 1, \sqrt{8} BM$
• C. $\pm \frac{3}{2} \sqrt{15} BM$
• D. $0, \sqrt{8} BM$

Answer 1

Answer: (C)

Atomic number $=7$
Structure is $1 s^2, 2 s^2, 2 p^3$

$n=3$,
Total spin $=\pm \frac{1}{2} n=\pm \frac{1}{2} \times 3=\pm \frac{3}{2}$
Magnetic moment $=\sqrt{n(n+2)}$ $=\sqrt{3(3+2)}=\sqrt{15} BM$