[Rutherford]

What are the values of the magnetic quantum number for subshell p(l=1)? Are they -1,0,1 in this sequence?

[XGen]

I believe yes.

[Rutherford]

Well, I was doing this problem:
Write the el. configuration of an atom, if his valent electrons have these properties:
n=4, l=0, m_l=0, m_s=+1/2
n=4, l=0, m_l=0, m_s=-1/2
n=4, l=1, m_l=0, m_s=+1/2
I thought that the configuration of the valent electrons would be: 4s² 4p², but in the answer it is 4s² 4p¹. I am really confused. How can that be right?

[Borek]

There are three electrons listed in the problem, why did you expect four?

[Rutherford]

Good point. But how can it be "4p¹" if m_l is 0? If I draw a p orbital diagram m_l=0 is the middle box I suppose. So the m_l=-1 box must be filled with 1 electron first and then the middle box.

[Borek]

No, there is no filling order of this type. We usually draw them starting with the left box, but it is just a meaningless convention.

[Rutherford]

Ok, thanks.