Question

The total value of m for the electrons (n = 4) is:

• A. 4
• B. 8
• C. 16
• D. 32

Answer 1

The correct option is C 16

The magnetic quantum number specifies the orientation in space of an orbital of given energy and shape. This number divides the subshell into individual orbitals which hold the electrons; there are $(2L+1)$ orbitals in each subshell. Thus, the $s$ subshell has only one orbital, the $p$ subshell has three orbitals, and so on.

For $n=4$, we have $s,p,d,f$ subshells.

For $s$ subshell, we have $2\times 0+1=1$.

For $p$ subshell, we have $2\times 1+1=3$.

For $d$ subshell, we have $2\times 2+1=5$.

For $f$ subshell, we have $2\times 3+1=7$.

The total value of m will be $1+3+5+7=16$

Hence, the correct option is $C$