Transition element valence electrons

[lovelearning]

In two different places, my PR Gen Chem review book states that the outermost d and f subshell electrons don't count as valence electrons for transition metals (just the outermost s electrons). However, I borrowed a friend's Kaplan review book which states that those d and f subshell electrons DO count, and has questions and answers to that effect.

I've looked at a couple of SDN threads and seen mixed answers about whether they count, and even from an online search (http://dl.clackamas.cc.or.us/ch104-06/valence_electrons.htm), it's clear that some of these electrons (particularly at the beginning of the subshell) can sorta behave like valence electrons, but many just act like shielding electrons.

My question is: for the purposes of the MCAT, should they be counted as valence electrons or not? (I understand that this is a black/white gross simplification given the info in the link I posted) Or are there certain cases when they should be viewed more as valence electrons than shielding electrons?

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[lovelearning]

bump...anyone?

 

[ZezKaiEll]

I don't know definitively one way or another, however since no one else has weighed in I'll give you my opinion. I was always taught in Gen Chem classes that d subshell electrons are neither truly valence nor core electrons.

 

[Patassa]

My question is: for the purposes of the MCAT, should they be counted as valence electrons or not? (I understand that this is a black/white gross simplification given the info in the link I posted) Or are there certain cases when they should be viewed more as valence electrons than shielding electrons?

Chances are if it's ambiguous and not taught in basic level classes or texts, you wont see a question on it. All questions I've seen so far dealing with transition metals have to do with oxidation state or emf. If someone asked me the valence of Tc I think my head might explode.