difference in p orbitals

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Katie Le 3K
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difference in p orbitals

Postby Katie Le 3K » Sun Nov 01, 2020 11:51 pm

In Prof. Lavelle's lecture, he writes

N, Z=7 1s^2 2s^2 2px^1 2py^1 2pz^1

I understand that its 2p^3 but how do I figure out the different px py pz?

rhettfarmer-3H
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Re: difference in p orbitals

Postby rhettfarmer-3H » Sun Nov 01, 2020 11:56 pm

its a rule that we will fill all orbitals first before we double up on orbitals. In the p section, there is 3 orbitals. So he gives different variable names x, y, z which can coordinate with any of them. it is referred to as the hundi rule.

sophie esherick 3H
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Re: difference in p orbitals

Postby sophie esherick 3H » Mon Nov 02, 2020 9:18 am

To figure out how many electrons fill each orientation, you have to remember that due to electron repulsion, electrons in the same subshell (s,p,d,f) must occupy different orbitals with parallel spin before adding another electron to the same orbital (Hund's Rule). px, py and pz are the three orientations of ml you can have (-1,0 and 1) and if there are three electrons then you know that each must be in a different state when applying Hund's Rule so you would get px1, py1 and pz1. Hope this helped!

JTieu_1L
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Re: difference in p orbitals

Postby JTieu_1L » Mon Nov 02, 2020 10:01 am

The px, py, and pz is specifying which orbital the electron is at in the p orbital. We know that the s orbital has only one orbital, the p orbital has 3 orbitals which can hold 6 electrons. Those three orbitals in the p subshell is px, py, and pz. If asked to draw the electrons in these subshells the question should specify which of the px, py, or pz it occupies.

Example: For Carbon, the electron configuration can be 1s^2 2s^2 2px^1 2py^1 or 1s^2 2s^2 2px^1 2pz^1 or 1s^2 2s^2 2py^1 2pz^1. The question would explicitly state if the electron is in px, py, or pz.

I hope this answers your question!

Emmeline Phu 1G
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Re: difference in p orbitals

Postby Emmeline Phu 1G » Mon Nov 02, 2020 11:51 am

Hi! In the lecture, I believe the professor wrote it like that to show that the 2p sub shell has three different orbitals. Since the p-orbital in general can hold up to 6 electrons, there are three possible orbitals (px, py, pz) to hold the electrons ( 2 e- in each). Due to Hund's rule, we would want to fill each orbital with one electron before putting a second electron into the same orbital to prevent electron-electron repulsion. Hope this helps! :)

Ximeng Guo 2K
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Re: difference in p orbitals

Postby Ximeng Guo 2K » Tue Nov 03, 2020 1:30 pm

px, py, pz are three different types of p-orbitals which are perpendicular to each other. It doesn't matter which one to be filled first.

Lorraine Jiang 2C
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Re: difference in p orbitals

Postby Lorraine Jiang 2C » Wed Nov 04, 2020 12:30 am

Hi! I think professor Lavelle mentioned that p orbitals have 3 parallel sub-orbitals: px, py, and pz, and each orbital can hold at most 2 electrons with opposite spins (ms). According to Hund's rule, we will fill one electron in all px, py, and pz sub-orbitals first before we started filling in the second electron in each sub-orbital.

Hope it helps!

Tae Pasawat 2A
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Re: difference in p orbitals

Postby Tae Pasawat 2A » Sun Nov 08, 2020 8:57 am

sophie esherick 2K wrote:To figure out how many electrons fill each orientation, you have to remember that due to electron repulsion, electrons in the same subshell (s,p,d,f) must occupy different orbitals with parallel spin before adding another electron to the same orbital (Hund's Rule). px, py and pz are the three orientations of ml you can have (-1,0 and 1) and if there are three electrons then you know that each must be in a different state when applying Hund's Rule so you would get px1, py1 and pz1. Hope this helped!


Hi! I have a follow up question! but if there were 4 electrons in the p subshell for example, will we know which one the 4th electron will fill first? or do the p subshells always start from x because it is the first in the alphabet? Or do the different p orbitals have different energy levels?

Charlotte Adams 1A
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Re: difference in p orbitals

Postby Charlotte Adams 1A » Sun Nov 08, 2020 9:49 am

Tae Pasawat 2A wrote:
sophie esherick 2K wrote:To figure out how many electrons fill each orientation, you have to remember that due to electron repulsion, electrons in the same subshell (s,p,d,f) must occupy different orbitals with parallel spin before adding another electron to the same orbital (Hund's Rule). px, py and pz are the three orientations of ml you can have (-1,0 and 1) and if there are three electrons then you know that each must be in a different state when applying Hund's Rule so you would get px1, py1 and pz1. Hope this helped!


Hi! I have a follow up question! but if there were 4 electrons in the p subshell for example, will we know which one the 4th electron will fill first? or do the p subshells always start from x because it is the first in the alphabet? Or do the different p orbitals have different energy levels?


I don't think it matters which one is filled first but in lectures Lavelle would usually have the first electron fill the px. Also the p orbitals are degenerate.


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