AP EAPCET 08-Jul-2022 Shift 1 Paper

For n=4 , four sub-shells namely 4s,4p,4d and 4f are possible.
Total number of electrons present in the sub-shell having ns value of

−1

2

is 16 .
Similarly, for n=3 , three sub-shell namely 3s,3p and 3d are possible. Totalnumber of electrons present in the sub-shell h aving ns value of −

1

2

is 9.
Thus, the sum of electrons present in all sub-shells of an atom with ms value of +

1

2

for n=4 and ms. value of −

1

2

for n=3 is 25 i.e (16+9) .