[kauzs-17]

We weren't taught ground-state electron configurations (we just did configurations based on the atomic number on the periodic table) but on our next exam our study guide has questions like "how many unpaired electrons does a ground state Zn have." But apparently ground state Zn is 2+. I was unaware. Is there some sort of trend for this kind of thing or is it just something you have to know.

[Borek]

Ground state is a metallic Zn.

[Corribus]

Ground state usually does not refer to what oxidation state it is. It refers to when all electrons in the system are at their lowest possible energies (states).  Zn²⁺ has a ground state, as does metallic zinc (Zn⁰). Neither Zn²⁺ nor Zn⁰ is the "ground state" of zinc, at least in the commonly accepted meaning of the term.

[Borek]

You are right, but I am somehow - in the context of earlier questions - suspecting the question is in fact about configuration of the element itself (in its ground state).

[Corribus]

I know, I was confused as well by the post, which is why I wonder whether he/she meant oxidation state or something rather than "ground state".

[antimatter101]

Think about atomic obitals - s, p, d, f.