## quantum Numbers

Monica Soliman 3F
Posts: 71
Joined: Wed Sep 30, 2020 9:57 pm

### quantum Numbers

I don't understand how the third part of the problem. Can someone explain how to get 2?
Attachments Bailey Giovanoli 1L
Posts: 74
Joined: Wed Sep 30, 2020 9:50 pm

### Re: quantum Numbers

So, in the solution to that problem, it states that when n, l, and ml are listed "regardless of the actual values an individual orbital can only hold two electrons." You can think back to in lecture how Dr. Lavelle showed how the p orbital is broken into an x, y, and z plane with each holding two electrons. This applies to the s, d, and f orbitals as well. So, for example this problem tells you you're looking at the d orbital as shown by l=2. Even though the d orbital can hold 10 electrons altogether, each ml value represents a set of paired electrons. This is why the d orbital can have ml values of -2,-1,0,1,2. Notice there are five ml values, each holding a max of 2 electrons. All together that will account for all 10 electrons in the d orbital.

Andreas Krumbein 1L
Posts: 59
Joined: Wed Sep 30, 2020 10:00 pm

### Re: quantum Numbers

So for the n quantum number, you find that by looking at what subshell it's in (an electron in the 4s subshell has quantum number n=4, an electron in the 2p subshell has the quantum number n=2).
For the l quantum number, the number is found by looking at what orbital it's in (l=0 for the s orbital, l=1 for the p orbital, l=2 for the d orbital, l=3 for the f orbital).
For the ml quantum number, this represents the orientation of the angular momentum within the orbital, and can be found by looking at the order of this particular element on a periodic table, and the numbers that this can be range from l to -l.
The ms quantum number represents the electron's spin, and can be found by looking at the order of this particular element on a periodic table.

But to specifically answer your question, if you are given the subshell (n), and the subshell is 1, then there can only be 2 electrons with that quantum number, if the quantum number is 2, then only 8 electrons can have that quantum number, and if it's less than 4, then only 18 electrons can have that quantum number, and if its greater than 4, then only 32 electrons can have that quantum number. If you are given a subshell and an orbital (n and l) then there can only be 2, 6, 10, or 14 electrons in an atom that could have this quantum number (varies depending on the orbital in question), and if you are given the subshell, the orbital and the orientation, (n, l, and ml) then there can only be 2, 3, 5, or 7 electrons with this quantum number (also varies depending on the orbital, and s orbital is a sphere without orientation).