Which of the following sets of quantum numbers could represent the last electron added to complete the electron added to complete the electron configuation for a ground state atom of `Br(Z=35)` according to Aufbau principle,

Options

A. 4, 0, 0, -1/2
B. 4, 1, 1, -1/2
C. 3, 1, 1, -1/2
D. 4, 1, 2, +1/2

Answer

B

Explanation

The valence shell configuration in `4s^(2) 4p^(5)`
`rArr` For the last electron : n = 4 , l = 1 .
m = - 1 , 0 or + 1, `S =(1)/(2) or -(1)/(2)`