gc question

[mg777]

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this problem is from ada sample test 2004

The electronic config. of a particular neutral atoms is 1s2 2s2 2p6 3s2 3p2
What is the number of unpaired electrons in this atom?

1
2
3
4
0

I think it is 2. The answer in the back says 3. I dont see it. Whois right? If someone see's this can u give me a brief explanation. thx!

 

[DrTacoElf]

this problem is from ada sample test 2004

The electronic config. of a particular neutral atoms is 1s2 2s2 2p6 3s2 3p2
What is the number of unpaired electrons in this atom?

1
2
3
4
0

I think it is 2. The answer in the back says 3. I dont see it. Whois right? If someone see's this can u give me a brief explanation. thx!

well i think it might be 3. Here is their reasoning. There are 3 p orbitals. The 3S and 3P orbitals are somewhat similar in engery (how much will answer the question really). If they are really close, e- can easily be promoted. If each P orbital has 1 unpaired e- this is more stable than one p orbital left unfilled. You will also see this trend in d block elements. Thus you end up with 3s1 3p3.

In any case this is a somewhat shady question up for debate. However if we had 4s2 3d4 you would get 4s1 3d5 for sure.

 

[sinned]

the answer is 2, I think the degenerates happen at the d-block and never heard of the s and p orbitals having degeneracy...and according to the reasoning that it becomes 3s1 3p3, that makes it four unpaired electrons which doesn't fulfill the answer of 3 as well...so I believe it is 2...

 

[DrTacoElf]

the answer is 2, I think the degenerates happen at the d-block and never heard of the s and p orbitals having degeneracy...and according to the reasoning that it becomes 3s1 3p3, that makes it four unpaired electrons which dont make fulfill the answer of 3 as well...so I believe it is 2...

good point, i overlooked that 😀

 

[sinned]

😉

 

[mg777]

yea i see your reasoning with the d-block. i didnt think of that. but it seems we're in agreement the answer is 2. i guess the hot shots at the ADA screwed up on this one. i hope their more careful with the real dat

 

[Blackstars]

Actually you screwed up. I just looked at my DAT packet and it has the answer as 2. Double check yourself 😀

 

[mg777]

actually youre wrong smart guy. you must have a different form. mine says the answer is 2. or maybe you screwed up. thanks

 

[DrTacoElf]

you guys must have different forms or something.

 

[mg777]

yea i just got mine when i was at UF for their dental program tour on thursday. mine says 2004 Dent. Adm. Test 04. Sample test items.

Ive seen some of these questions in kaplan's q bank at kaptest.com

 

[dane4695]

Yeah I don't think at that energy level you can have a jump like someone was saying. The differencec in energy is too great, 1/Ni^2-1/Nf^2 ... i remember reading that somewhere, which makes it harder in the lower orbitals. It should be two, but i think that's already the conclusion 🙂