From: BenP (bpitt@n2.com)
Date: Wed Jan 26 2000 - 08:21:53 PST
Date: Wed, 26 Jan 2000 08:21:53 -0800 From: "BenP" <bpitt@n2.com> Message-ID: <GECJAFKLKJGBAAAA@shared1-mail.whowhere.com> Subject: Transition Metals - help!
Hi everyone,
My eighth graders and I need some help that I cannot give, yet. We're discussing how the elements can be grouped by characteristics. Mostly I've had success, but in the Transition Metals I am having trouble getting a firm grip on the basis for this concept of "variable valences." The concept of valence electrons is easy when they are all in the outermost shell, but when we drop down into the inner shells it gets a bit spooky for me. I understand that as we progress across the transitions we progressively see atoms with more electrons in their inner d and f sublevels. That I've explained. But what is it about the inner d and f orbitals that causes the multiple valences? Logically all these elements just have two valence electrons, but this seems to defy logic somewhat. (I have this fear that this is asking something that I should know like the months of the year, but I don't, so be gentle!) What do we know that tells us WHY these elements tend to form different ions? It is all a bit slippery to me ri
ght now, and some of my students are at least asking, so I want not to mislead them or leave their questions unanswered.
If you can summarize it in this forum, great! Or if you can help me understand better so I can better explain the underlying theory please email me with your phone number and a time I can reach you to discuss this. It has a bit of urgency to it.
Ben Pittenger
bpitt@n2.com
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