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

Explanation

For n=4, Four sub-shell namely 4s, 4p, 4d and 4f are possible. Total number of electrons present in these sub shell having `m_(s)` value of -1/2 is 16.