Confused about definition of valence electron

[Dorfl]

This is a very simple chemistry question, but I've failed to find an unambiguous answer to it in any of my textbooks:

Are the valence electron the electrons in the outermost shell, or the outermost subshell? For example, does oxygen have 6 valence electrons – all the ones in the L shell – or just 4 – the ones in the 2p subshell?

Thanks in advance

 

[drkitten]

This is a very simple chemistry question, but I've failed to find an unambiguous answer to it in any of my textbooks:

Are the valence electron the electrons in the outermost shell, or the outermost subshell? For example, does oxygen have 6 valence electrons – all the ones in the L shell – or just 4 – the ones in the 2p subshell?

Thanks in advance

My understanding is that the valence electrons are the ones in the outermost shell. Things get a little tricky when you get into the transition metals and rare earths and whatnot, of course, precisely because the outermost subshell is not usually part of the outermost shell, which is one reason that you get multiple oxidation states.

Wikipedia discusses this in depth.

 

[Dorfl]

My understanding is that the valence electrons are the ones in the outermost shell. Things get a little tricky when you get into the transition metals and rare earths and whatnot, of course, precisely because the outermost subshell is not usually part of the outermost shell, which is one reason that you get multiple oxidation states.

Wikipedia discusses this in depth.

Thanks

The book I was reading sounded like it was saying one thing, then went on as though it had said the other. It's a bit unsettling, if useful, how wiki articles are usually clearer than books written specifically to teach the article's subject.

 

[drkitten]

Thanks

The book I was reading sounded like it was saying one thing, then went on as though it had said the other. It's a bit unsettling, if useful, how wiki articles are usually clearer than books written specifically to teach the article's subject.

"Many eyes."

The Wikipedia article has been rewritten dozens if not hundreds of times. There's no way any publisher/editor could put that kind of work into a full book.

The flip side of that is at least 5% of the hundreds of rewrites actually got it wrong and made it substantially worse. Books are generally better controlled for accuracy and less for readability,... unless you're selling science texts to Texas, of course.

 

[Madalch]

My understanding is that the valence electrons are the ones in the outermost shell. Things get a little tricky when you get into the transition metals and rare earths and whatnot, of course, precisely because the outermost subshell is not usually part of the outermost shell, which is one reason that you get multiple oxidation states.

Wikipedia discusses this in depth.

Pretty much correct. For groups IA and IIA, it's just the s electrons. For the transition metals, it's the s and d (and f for the inner transition metals, or lanthanides/actinides); for groups IIIA to the noble gases, it's the s and p.

For zinc and the others in group IIB, it's only the s.