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### homework 2.43 part e

Posted: Sat May 05, 2018 10:55 pm
The question asks what is the ground-state electron configuration expected for each of the following elements: (e) tungsten?
The answer is: [Xe] 4f^14 5d^4 6s^2
I understand where the 5d^4 and 6s^2 came from, however, I'm still confused on how to get 4f^14. Can someone please explain?

### Re: homework 2.43 part e

Posted: Sat May 05, 2018 11:01 pm
the answer is 4f^14 because you need to include the configuration for the f-block, so not including La, there would be 14 e- total.

### Re: homework 2.43 part e

Posted: Sat May 05, 2018 11:06 pm
I see. So the f block lies in between the 6s-7s and 5d/6d rows?

### Re: homework 2.43 part e

Posted: Sat May 05, 2018 11:57 pm
Vivian Gonzalez 1A wrote:I see. So the f block lies in between the 6s-7s and 5d/6d rows?

Yes it does. If you look at the periodic table there should be 2 boxes labelled "57-71 lanthanoids" and "89-103 actinoids", where that section leads to the portion below as an extension.

### Re: homework 2.43 part e

Posted: Sun May 06, 2018 2:32 pm
But why is it 5d^4 6s^2 and not 5d^5 6s^1? I thought it was more stable to have d^5 than d^4 (as well as d^10 instead of d^9)?

Also are we expected to know how to include the f-block in electron configurations? I'm not sure but I thought we had to know how to do electron configurations of the s-block, the p-block, and the first row of the d-block. Or did I misunderstand that?

Thank you!! :)
Anna De Schutter - section 1A

### Re: homework 2.43 part e

Posted: Mon May 07, 2018 1:32 pm
Anna De Schutter - 1A wrote:But why is it 5d^4 6s^2 and not 5d^5 6s^1? I thought it was more stable to have d^5 than d^4 (as well as d^10 instead of d^9)?

Also are we expected to know how to include the f-block in electron configurations? I'm not sure but I thought we had to know how to do electron configurations of the s-block, the p-block, and the first row of the d-block. Or did I misunderstand that?

Thank you!! :)
Anna De Schutter - section 1A

I have the same question. Why would it not be $5d^{5}6s^{1}$

### Re: homework 2.43 part e

Posted: Mon May 07, 2018 1:40 pm
I'm also slightly confused with this problem. Why does 4f^14 come before 5d^4 and 6s^2?

### Re: homework 2.43 part e  [ENDORSED]

Posted: Mon May 07, 2018 3:36 pm
viewtopic.php?f=20&t=31289&p=99159&hilit=tungsten&sid=842f05fb5698f1c9857c0aa71062966f#p99159

See this post for an explanation on Tungsten stability.

As for why the 4f14 comes first, some choose to list it in order of the value of n. As for how it's filled, see the attached picture.

### Re: homework 2.43 part e

Posted: Sat May 12, 2018 12:34 pm
Doesn't 4f^14 come first because when doing electron configurations, you list it in increasing principal quantum number(n)?