Lecture confusion in quantum numbers

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Adrienne Chan 1G
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Joined: Wed Sep 30, 2020 9:40 pm

Lecture confusion in quantum numbers

Postby Adrienne Chan 1G » Fri Oct 23, 2020 11:31 am

In today's lecture, Lavelle gave an example in the slideshow that said when n=2, l=1, and ml=-1, the electron is in the 2px state. But then on the whiteboard he wrote the same thing but said that ml=+1. Could someone please explain which one it is?

Chance Herbert 1A
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Joined: Wed Sep 30, 2020 9:55 pm

Re: Lecture confusion in quantum numbers

Postby Chance Herbert 1A » Fri Oct 23, 2020 11:51 am

I believe the 2px state would correspond to n=2,l=1, and ml=-1! If ml were equal to +1 I believe this would be 2pz

David Facio 1K
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Re: Lecture confusion in quantum numbers

Postby David Facio 1K » Fri Oct 23, 2020 12:08 pm

Quantum Numbers

Principle: (n)

Angular Momentum: (L)

Magnetic: (m_l)

Spin: (m_s)



The second shell (n=2) has two subshells (L= 0 and L= 1)


L=1 is the p-subshell and it has three possible orbitals where m_l can be (-1, 0, 1)

I think for that example he was saying that the value of -1 specifically tells us that the orbital is in the 2_px state of the 3D model.
Last edited by David Facio 1K on Sun Oct 25, 2020 1:01 am, edited 1 time in total.

Samantha Lee 1A
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Joined: Wed Sep 30, 2020 10:05 pm

Re: Lecture confusion in quantum numbers

Postby Samantha Lee 1A » Fri Oct 23, 2020 12:34 pm

The px orbital is -1 for ml. There are three p sections (px, py, pz). Px corresponds to ml -1, py is ml 0 and pz is ml 3. Hope that helps. Looking at it visually on the diagram shown in lecture is helpful as well.

Anna Yang 2A
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Joined: Wed Sep 30, 2020 9:43 pm

Re: Lecture confusion in quantum numbers

Postby Anna Yang 2A » Fri Oct 23, 2020 1:08 pm

Within the second shell (n=2), the shape (l) can take on either a p- or s-orbital. Since l=1 in this instance, it corresponds with the p-orbital, which has the possibilities for the value of ml being -1, 0- or 1. With these, px is interchangeable with -1, py with 0, and pz with +1. So in this case, 2px would mean ml = -1.

Emilie_Paltrinieri_1K
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Joined: Wed Sep 30, 2020 10:07 pm

Re: Lecture confusion in quantum numbers

Postby Emilie_Paltrinieri_1K » Sun Oct 25, 2020 10:21 am

What does a 2px state represent?

Sofia Lombardo 3F
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Joined: Wed Sep 30, 2020 9:31 pm

Re: Lecture confusion in quantum numbers

Postby Sofia Lombardo 3F » Sun Oct 25, 2020 11:23 am

ml is the magnetic quantum number and it can be any value between -l and l. In the lecture example l = 1, which means that the ml can equal -1,0,1. From my understanding, the px goes with -1, py with 0, and pz with 1.


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