Question

which of the following sets of quantum numbers (n,l,ml,ms) describes the electron which is most easily removed when a sodium aton is converted to a sodium ion?
a)2,1,0,-1/2
b)2,0,0,-1/2
c)3,1,1,+1/2
d)3,2,1,-1/2
e)3,0,0,+1/2
can anyone explain this so I understand it?

Answer 1

I can.
Na is atomic number 11 meaning it has 11 electrons. How are they arranged.
1s2 2s2 2p6 3s1. So the outside electron is a 3s electron.
N = 3 is the third shell.
l can have values of 0, 1, 2, 3, etc up to a maximum of n-1 (in this case it can have 0 since there is only 1 electron with which to contend.)
ml can have values of -l to +l in increments of 1 unit and zero is included. When l is 0, ml can be ONLY 0 (-0 to +0 doesn't mans much sense).
ms is EITHER +1/2 or -1/2. With only one electron we usually give it the +1/2 for the first one and -1/2 for the second one.
So the values are
n=3
l=0
ml=0
ms=+1/2
The answer can be ONLY e.