Electron Shells

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Kailani_Dial_2K
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Electron Shells

Postby Kailani_Dial_2K » Fri Oct 30, 2020 8:19 pm

Hi so I was wondering if someone could explain to me why n=3 has sub shells 3s, 3p, and 3d. I thought that the subshell 3d didn't come in until the n=4 .
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Arieanne De Guzman 2J
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Re: Electron Shells

Postby Arieanne De Guzman 2J » Fri Oct 30, 2020 8:57 pm

Hi! The quantum number n tells us how many subshells make up that shell. For example, n=1 has one subshell: 1s, n=2 has two subshells: 2s, 2p, n=3 has three subshells: 3s, 3p, 3d, and so on. Hope this helps!

Kailani_Dial_3G wrote:Hi so I was wondering if someone could explain to me why n=3 has sub shells 3s, 3p, and 3d. I thought that the subshell 3d didn't come in until the n=4 .

Lizbeth Garcia 1F
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Re: Electron Shells

Postby Lizbeth Garcia 1F » Fri Oct 30, 2020 9:24 pm

If I remember correctly, the n=4 only comes before 3d for the two elements under the s-block. From there it goes back to n=3 including the 4s that were previously used. However, like how the previous posts says, the n states how many subshells there are.

BaileyB1F
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Re: Electron Shells

Postby BaileyB1F » Fri Oct 30, 2020 9:36 pm

https://www.google.com/url?sa=i&url=htt ... AdAAAAABAD

This image shows the orbital diagram. This just helps to visually describe the how they're arranged.

Kailani_Dial_2K
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Re: Electron Shells

Postby Kailani_Dial_2K » Mon Nov 02, 2020 3:16 pm

Arieanne De Guzman 2J wrote:Hi! The quantum number n tells us how many subshells make up that shell. For example, n=1 has one subshell: 1s, n=2 has two subshells: 2s, 2p, n=3 has three subshells: 3s, 3p, 3d, and so on. Hope this helps!

Kailani_Dial_3G wrote:Hi so I was wondering if someone could explain to me why n=3 has sub shells 3s, 3p, and 3d. I thought that the subshell 3d didn't come in until the n=4 .


Hi Arieanne so I understand that the quantam number gives the number of subshells, my question more pertains to how this lines up with the periodic table. So on the periodic table when you do the electron configuration for let's say chlorine, there is no d subshell that is included. It is just [Ne]3s^2 3p^5. However, when you go to the next row, n=4, for lets say Bromine, within the elctron configuration the d subshell is included. So what I don't understand is conceptually why in the n=3 level are we including subshell d, if when we do e- configurations using the periodic table all of the elements in the n=3 row do not have electrons in the d subshell. If you could explain that to me that would be great. I might just be overhinking it but I can't wrap my head around it. Thank you!

Ria Nawathe 1C
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Re: Electron Shells

Postby Ria Nawathe 1C » Mon Nov 02, 2020 3:25 pm

The angular momentum quantum number l, which tells us about the subshells in each shell, is determined by the principle quantum number (n=3 in this case). For n=3, l can be 0...n-1 which is 0, 1, and 2, corresponding to s, p, and d.

Kailani_Dial_2K
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Re: Electron Shells

Postby Kailani_Dial_2K » Mon Nov 02, 2020 3:46 pm

Ria Nawathe 2B wrote:The angular momentum quantum number l, which tells us about the subshells in each shell, is determined by the principle quantum number (n=3 in this case). For n=3, l can be 0...n-1 which is 0, 1, and 2, corresponding to s, p, and d.


Ria you are my hero, I was thinking of it in relation to the periodic table, but that makes so much more sense. I overcomplicated it in my head beyond belief. Thank you so much for the help!!

Arieanne De Guzman 2J
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Re: Electron Shells

Postby Arieanne De Guzman 2J » Fri Nov 06, 2020 12:05 pm

I apologize for misunderstanding your question! You are indeed correct that the electron configurations do not have electrons in the d subshell and that it only comes up in n=4. However, it is important to note that the 4s subshell gets filled up before the 3d subshell. This is because it has less energy. Therefore, 3d is actually seen in electron configurations in the 4th row of the periodic place. You'll actually see this pattern as you go down the rows of the periodic table. I think the most helpful thing I could say is that the subshells in the periodic table are not dependent on the row and are more so dependent on its energy which can be derived from the quantum numbers. Ria has mentioned the angular momentum quantum number l, and you can actually find the energy of each subshell with n+l. Knowing that l = n-1, you can find the energy of the 3d subshell and the 4s subshell: 3+2=5 and 4+0 = 4. Here we can see the energy of the 4s subshell is lower than the 3d subshell, thus it gets filled up first and the 3d subshell gets filled after! Here is a diagram that helped me with electron configurations in high school, it shows which subshells get filled up first: http://antranik.org/wp-content/uploads/ ... ration.jpg

I hope this wasn't too confusing and helped you understand more on why 3d comes up in the 4th row despite being associated with n=3.

Kailani_Dial_3G wrote:
Arieanne De Guzman 2J wrote:Hi! The quantum number n tells us how many subshells make up that shell. For example, n=1 has one subshell: 1s, n=2 has two subshells: 2s, 2p, n=3 has three subshells: 3s, 3p, 3d, and so on. Hope this helps!

Kailani_Dial_3G wrote:Hi so I was wondering if someone could explain to me why n=3 has sub shells 3s, 3p, and 3d. I thought that the subshell 3d didn't come in until the n=4 .


Hi Arieanne so I understand that the quantam number gives the number of subshells, my question more pertains to how this lines up with the periodic table. So on the periodic table when you do the electron configuration for let's say chlorine, there is no d subshell that is included. It is just [Ne]3s^2 3p^5. However, when you go to the next row, n=4, for lets say Bromine, within the elctron configuration the d subshell is included. So what I don't understand is conceptually why in the n=3 level are we including subshell d, if when we do e- configurations using the periodic table all of the elements in the n=3 row do not have electrons in the d subshell. If you could explain that to me that would be great. I might just be overhinking it but I can't wrap my head around it. Thank you!


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