(a) How many sub - shells are associated with m=4
(b ) How many electron will be present in the sub - shells having m value of `(1)/(2) ` for n= 4 ?

Explanation

(a) n=4 so no of subshell =4 for n=4 the value of l and subshell is as follows

(b ) `m_(1) = (1)/(2) ` and n=4 so no of electron =16
n=4 no of orbital there are two electron in which one has `m_(s) + (1)/(2)` and other `m_(s) = (1)/(2)`
So `m_(s ) - (1)/(2) ` and n=4 such 16 electron .