# Electron Configurations Question

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#### Saber tooth

##### Hunting For The Prey:DATs
10+ Year Member

When asked to say how many unpaired electrons are in an electron configuration we simply look at the valance shell and count the number of unpaired electrons: i.e.

1S^2 2S^2 2P^3 the valance electron are in the P orbital and there are three unpaired electrons

However when having electron configurations of higher #'s a bit of interesting thing occures

i.e. ...4s^2 3d^6

here do we look at the Valance electrons
(4s orbital) or do we look at the orbital with higher energy (the 3d orbital)

A) agree with 4s orbital (therefore in this case Zero unpaired electrons)
B) agree with 3d orbital (therefore in this case Four unpaired electrons)

Interested?

#### nate28

##### Full Member
10+ Year Member
7+ Year Member
When asked to say how many unpaired electrons are in an electron configuration we simply look at the valance shell and count the number of unpaired electrons: i.e.

1S^2 2S^2 2P^3 the valance electron are in the P orbital and there are three unpaired electrons

However when having electron configurations of higher #'s a bit of interesting thing occures

i.e. ...4s^2 3d^6

here do we look at the Valance electrons
(4s orbital) or do we look at the orbital with higher energy (the 3d orbital)

A) agree with 4s orbital (therefore in this case Zero unpaired electrons)
B) agree with 3d orbital (therefore in this case Four unpaired electrons)

Interested?

I'd say B: 3d orbitals w/ 4 unpaired electrons b/c it sounds like the question is asking how many electrons are unpaired.

#### TimeforDAT

##### Full Member
10+ Year Member
I'd say B: 3d orbitals with four unpaired electrons because the 4s orbital fills before the 3d..so then you get four electrons going into the 3d orbitals last.

#### joonkimdds

##### Senior Member
10+ Year Member
7+ Year Member
i.e. ...4s^2 3d^6

here do we look at the Valance electrons
(4s orbital) or do we look at the orbital with higher energy (the 3d orbital)

A) agree with 4s orbital (therefore in this case Zero unpaired electrons)
B) agree with 3d orbital (therefore in this case Four unpaired electrons)

Interested?

I thought d orbital doesn't have anythhing to do with valence electrons since there can be total of 8 valence electrons, 2 from s orbital and 6 from p orbital.

so for the example you gave us, I believe it has 2 valence electrons at S orbital and 0 valance electrons at p orbital.

I choose A C

#### cheezer

When asked to say how many unpaired electrons are in an electron configuration we simply look at the valance shell and count the number of unpaired electrons: i.e.

1S^2 2S^2 2P^3 the valance electron are in the P orbital and there are three unpaired electrons
The valence electrons are in the second shell, the unpaired electrons are in the p orbital.

However when having electron configurations of higher #'s a bit of interesting thing occures

i.e. ...4s^2 3d^6

here do we look at the Valance electrons
(4s orbital) or do we look at the orbital with higher energy (the 3d orbital)

A) agree with 4s orbital (therefore in this case Zero unpaired electrons)
B) agree with 3d orbital (therefore in this case Four unpaired electrons)

Interested?
If they're asking how many unpaired electrons are in an electron configuration, then I'd look at the orbitals that still needs electrons. Whether they're valence and/or the energy of the orbital shouldn't matter, only the fact that they're unfilled should matter. In this case I'd look at the 3d orbital.

#### Saber tooth

##### Hunting For The Prey:DATs
10+ Year Member
THanks for clearing things up... it seems like that the question is how many unpaired electrons are there thats why B) is correct