Ground state... of Ions???

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ridethecliche

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From EK Chem in chapter exam.

17) Which of the following species has an unpaired electron in its ground-state electronic configuration?

A)Ne
B)Ca+
C)Na+
D)O^2-

The answer is B, but I thought it was Na+, as Na (ground state) has an unpaired e-.

I can see that Ca+ has an unpaired electron, but it doesn't in the ground state, right?

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When Na loses an electron, it removes its 3s1 electron and it's valence becomes 2p6 and takes the configuration of Neon. Px,Py,Pz all have paired eletrons.

When Ca loses an electron, it becomes Ca+ and takes the electron configuration of Na and has a valence of 3s1 (unpaired 3s oribtal).
 
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I guess I'm a little lost at how/why ground state refers to ions...

Ground state refers to the lowest energy state regardless of whether it is an atom OR an ion.

You are considering ions as being excited states and that is not true.
 
I'm just wondering why the groundstate of calcium is Ca+, and not Ca.

Ground state of Ca is the ground state of Ca. Ground state of Ca+ is the ground state of Ca+. They're different species. You're thinking of Ca+ as the excited state of Ca, because an electron has to be removed from Ca. But that's not the point of the question. The question had to include the words ground state, because if it didn't, then any species can have unpaired electrons. One electron can jump from a lower to a higher energy orbital, thus creating unpaired electrons.
 
Ground state of Ca is the ground state of Ca. Ground state of Ca+ is the ground state of Ca+. They're different species. You're thinking of Ca+ as the excited state of Ca, because an electron has to be removed from Ca. But that's not the point of the question. The question had to include the words ground state, because if it didn't, then any species can have unpaired electrons. One electron can jump from a lower to a higher energy orbital, thus creating unpaired electrons.

Ah. Thanks :)
 
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