Unpaired electrons/transition metal ions
 

Hi,

My question concerns this homework problem I have:

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"How many unpaired electrons are there in the following transition metal ions. Write your answer as a sequence of numbers, for example, 23542141.

A) Mn5+ B) Fe3+ C) V5+ D) Fe4+ E) Mn4+ F) Ni4+ G) Cu4+ H) Sc2+ "

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My text wasn't really helpful. So, wouldn't these be the answers for e/one? 25043651

For example, for Mn5+ I picked 2 (2 unpaired e-'s) b/c the config. is 4s2 3d5. so that is 5 + 2 = 7 unpaired electrons, minus 5 (Mn5+) = 2. Is this the right way to think about it?

And for instance, for V5+ I said..... since it's s2 d3, that = 5 unpaired electrons, and so 5-5 = 0. So am thinking it through the right away? And what about Cu4+, since it is one of the exceptions having a config of s1 d10?


Thanks in advance for any help

just wondering, is this kind of problem beyond the ken of the chemistry experts on this board?

you must remember that transitions metals lose the 4s electrons FIRST before losing the 3d electrons.

eg Mn2+ is [Ar]4sº 3d5 - therefore 5 unpaired electrons