Question

Give the set of four quantum numbers that could represent the last electron added (using the Aufbau principle) to the Cl atom.A) n=3, l=1, ml=1ms=+12B) n=3, l=0, ml=1, ms=−12C) n=3, l=2, ml=1, ms=+12D) n=2, l=1, ml=1, ms=−12E) n=3, l=1, ml=1, ms=−12

Answer 1

n=3, l=1, ml=1ms=+1/2

Explanation:

The electron configuration of chlorine atom is; [Ne] 3s² 3p⁵.

This means that the last electron is found in a 3pz orbital.

We can see that the principal quantum number is 3. The electron is in a p orbital so l=1, the electron must be found in a 3pz orbital hence ml=1. The electron is found alone in that orbital hence s= 1/2.