Predict total spin for each configuration :
(A) `1s^(2) " " (B) 1s^(2),2s^(2),2p^(6)`
(C ) `1s^(2),2s^(2),2p^(5) " " (D) 1s^(2),2s^(2),2p^(3)`
(E) `1s^(2),2s^(2)2p^(6),3s^(2) 3p^(6)3d^(5),4s^(2)`

Explanation

Total spin = No. of unpaired electron `xx(pm(1)/(2))`
(a) Total spin in `1s^(2)=0xx(pm(1)/(2))=0`
(b ) Total spin in `1s^(2),2s^(2),2p^(6)=0xx(pm(1)/(2))=0`
(c ) Toal spin in `1s^(2),2s^(2),2p^(5)=1xx(pm(1)/(2))=(pm(1)/(2))`
(d) Total spin in `1s^(2),2s^(2),2p^(3)=3xx(pm(1)/(2))=(pm(3)/(2))`
Total spin in `1s^(2),2s^(2),2p^(6),3s^(2),3p^(6),3d^(5),4s^(2)=5xx(pm(1)/(2))=(pm(5)/(2))`