Gen Chem - DAT Destroyer question

[NDPitch]

I just finished my last batch of problems in 2012 destroyer. The last 36 questions in that book are the most challenging I think. I got owned, and did pretty well on the other stuff.

Anyway, this question asked...

Which set of quantum numbers best describes a valence electron in Germanium?

I narrowed it down to these, because can't both of these be possible???

4,0,0,1/2
4,1,1,1/2

The first set depicts a 4s valence, and the other a 4p valence. Aren't the valance electrons for Germanium 4s2, 2p2? According to Chad, once the d orbitals are full, those don't count as valance. But according to destroyer, the only correct one is the one that depicts a p valence electron. S isn't possible?

Thoughts?

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[NDPitch]

Stumped?

 

[joeeeey3]

hmmm yeah Germanium does indeed have 4 valence electrons; 2 in S orbital and 2 in p orbital. so I suppose both choices would be correct since the first choice describes the electron in s orbital and second choice for the p orbital. but..... I guess you are supposed to assume that they are asking for the electron at the very far end which is p orbital.

 

[412smb412]

I just finished my last batch of problems in 2012 destroyer. The last 36 questions in that book are the most challenging I think. I got owned, and did pretty well on the other stuff.

Anyway, this question asked...

Which set of quantum numbers best describes a valence electron in Germanium?

I narrowed it down to these, because can't both of these be possible???

4,0,0,1/2
4,1,1,1/2

The first set depicts a 4s valence, and the other a 4p valence. Aren't the valance electrons for Germanium 4s2, 2p2? According to Chad, once the d orbitals are full, those don't count as valance. But according to destroyer, the only correct one is the one that depicts a p valence electron. S isn't possible?

Thoughts?

Germanium has 4 valence electrons. 2 in s orbital, and 2 in the p orbital. it can only be: 4,0,0, 1/2 since the third suborbital of the p is NOT FILLED, only the -1 and 0 have an electron each.

 

[joeeeey3]

Germanium has 4 valence electrons. 2 in s orbital, and 2 in the p orbital. it can only be: 4,0,0, 1/2 since the third suborbital of the p is NOT FILLED, only the -1 and 0 have an electron each.

first of all, the correct answer is 4,1,1 1/2
you can check from destroyer, it is number 261

second of all, you don't have to always fill up -1 orbital first. You are free to fill up 1 then 0 then -1. However, this is not something you need to know for DAT, this is a miscellaneous info I learned from upper class Inorganic chem.

just letting you know. hope that didnt confuse you further tho haha

 

[NDPitch]

There seems to be a lot of disagreement on this. I still say both are possible. If not, why?! I know what destroyer says the answer is, but that doesn't mean it's right.

 

[412smb412]

first of all, the correct answer is 4,1,1 1/2
you can check from destroyer, it is number 261

second of all, you don't have to always fill up -1 orbital first. You are free to fill up 1 then 0 then -1. However, this is not something you need to know for DAT, this is a miscellaneous info I learned from upper class Inorganic chem.

just letting you know. hope that didnt confuse you further tho haha

ya i've heard about that as well. but the way u fill it up is just convention? either way i still don't understand how this electron is not considered valence, both should be correct answers since its valence is 4, just like carbon...

 

[NDPitch]

ya i've heard about that as well. but the way u fill it up is just convention? either way i still don't understand how this electron is not considered valence, both should be correct answers since its valence is 4, just like carbon...

I'm gonna go ask Chad. Maybe he can shed some light.

 

[NDPitch]

For those still curious...Chad has spoken...


I've been asked this one before and you're correct in saying that both the 4s and 4p (you meant to say 4p2 above fyi) are considered valence electrons and so there are technically 2 correct answers for this question.

Hope this helps!

 

[Michaelnsu]

Thanks for clearing this up..

 

[biomolecmed]

I saw that question also. I went to a few chemistry professors at my school. They told me that the answer in the book is correct. You always look at the outermost energy level to figure out the valence electrons. So 4p2 would be your answer. Hope this helps.

 

[ToBeDDSS]

The answer is 4,1,1 1/2.
When i did this question way back i got it wrong so I asked my Chem professor and he told me that you only consider the outer most shell. for example if you have 1s2 2s2 2p3 you only consider 2p3 because it's the furthest from the nucleus. He told that it"s a common mistake that he sees a lot when dealing with quantum numbers.
hope this helps

 

[412smb412]

I saw that question also. I went to a few chemistry professors at my school. They told me that the answer in the book is correct. You always look at the outermost energy level to figure out the valence electrons. So 4p2 would be your answer. Hope this helps.

Hmm. The only thing that doesn't
Match with that description is that if
Applied to let's say carbon, it would suggest carbon having 2 valence electrons...

Any1 know of any questions like this in the actual DAT?

 

[ktran17]

lets do some pchem!!!

Although there are valence electrons in the 4s and 4p orbital, since the p orbitals encompass a greater radius, you're more likely going to remove the valence electrons in the p-orbital first. This is because p orbitals stick out like dumbells and therefore its electron density covers a greater 3-d spatial area.

Since the question asked for the set of quantum numbers that "best" describes the valence electron we would assume that we're looking at the p-orbital valence electron.


This is my guess at least