Why vary from IUPAC for lanthanoids and actinoids?

Webelements provides a valuable service and I'd like to help make it better.

IUPAC's "Nomenclature of Inorganic Chemistry" (1990) redbook p 43 I-3.8.2 calls Lu a lanthanoid and Lr an actinoid. The provisional redbook about to come out will say the same thing. Webelements own entry for Lu essentially says it's isolated from other lanthanoids. So why have a row labelled "lanthanoids" that are a different color and in a different location than Lu? Lu is a "d-block lanthanoid" in a similar manner (in terms of nomenclature at least) to He being an "s-block noble gas," yes?

I know I'm supposed to refer to J. Chem Ed. (1982) 59 634-636 by W.B. Jensen and I'm in the library reading it now. It presents great evidence to support its conclusion: "All of these properties unanimously favor the placement of lutetium and lawrencium, rather than lanthanum and actinum, in group IIIB [below Y]" and I agree. If I were forced to either place La/Ac below Y or Lu/Lr there, I'd pick Lu/Lr like you have done, but the 18-column table that IUPAC uses puts both there along with everything in between because they're all called lanthanoids. OK...of course, the 32-column IUPAC table makes the most sense, but we're not talking about the 32-column table.

Now make fun of me, call me obsessive and a pedant, talk about it all being semantics, imply I'm supposed to dislike IUPAC for some reason, say I should get back to work doing something to make money or help the world, and you'll be right on all counts. Then please think of countless classrooms around the world where a table that makes it plain that Lu is a lanthanoid differs from your table and think of countless children and teachers who are stumped--like me--about why information on the internet has to be so inconsistent with accepted practice.

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I wish I could get to sit on a IUPAC quango one day,
sipping Pina Colladas in the Bahamas as we decide that
helium should henceforth be known as heelon. :roll:

Nope, Lu and Lr and NOT f-blocks. They're d-blocks. Therefore, they're not rare-earths.

refer to the sequence of electronic placement:

1s, 2s, 2p ... 5p, 6s, [color=red]4f, 5d[/color] ...

For 88, the electrons will fill up everything from 1s to 4d. And when it goes to Lu, one more electron is placed down and it MUST hop into 5d. Therefore, it is a d-block element.

since when did the Aufbau principle ever hold hard and fast?

Even for ground states?

At room temperature, in real molecules, a whole boltzmann spread of different energy states are occupied.

Real life and real chemistry are never as simple as IUPAC and their quango-driven Asperger's syndrome...

Yes. Lu and Lr are d-block elements. Lu is a d-block lanthanoid and also a rare earth element. Lr is a d-block actinoid. Why? Because IUPAC (the quango) has a naming system for collective names of groups of elements and every little boy and girl in chemistry class learns about the nice important scientists who put things into categories and then give the categories names and then go out for drinks and a show. What? Lu not a lanthanoid? Next someone online with an otherwise-wonderful web site will say that methane isn't an alkane because it's so little.

The colors and positions at http://www.iupac.org/didac/Didac%20Eng/Didac01/Content/S29.htm make this clear. WebElements doesn't, so (in my opinion) either the bottom two rows should be labeled "f-block elements" instead of lanthanoid/actinoid, or, it should look like the IUPAC table, or at least it should be made clear that Lu is a lanthanoid and Lr is an actinoid.

My God, man, think of the children. The children!

I'd be prepared to wager a substantial sum of cash that none of us have ever held a piece of lawrencium in our hands ever, much less explored its chemistry.

Just to re-iterate -

those electron configurations you see textbooks are for
UNBOUND MONATOMIC GAS PHASE NEUTRAL ATOMS!

Now excuuuuuuuuuuuuuuuuuuse me,
but I doubt that many of you are going to be working with monatomic gaseous lutecium so long as you live!

That's all very true. It's also true that nobody on the planet has even seriously claimed to have ever been anywhere near a single atom of ununseptium, but that's on the webelements table, and it should be.

Just to reiterate my point...

Let's say I want to buy a few grams of lutetium as a gift for my sweet nerdy girlfriend to add to her element collection. Will it be sold by the Taishan Rare Earth Canada Company of Richmond BC? http://www.rare-earth.ca/prd/index.html

Of course it will. They sell rare earths, IUPAC repeats the convention that lutetium is a rare earth lanthanoid, so Taishan sells lutetium.

[quote="feline1"]I'd be prepared to wager a substantial sum of cash that none of us have ever held a piece of lawrencium in our hands ever, much less explored its chemistry.[/quote]

I've held a few atoms of it in my hands. I didn't explore its Chemistry though. Can I have the money?

Does it REALLY matter what goes exactly where?
As long as you know what order they are in, and their general uses, that's all that really matters.

And anyways,
by the time you get down to lawrencium,
the orbital approximation is in tatters!

Please don't forget that this nice idea of individual electrons whizzing around on individual orbitals is just a mathematical approximation to the analytically-insoluble multi-body Schroedinger equations.

Down in periods 6 and 7, increasingly strong spin orbit coupling makes such a mess of things that pontificating about "d orbitals" is highly dubious anyways.

NEXT WEEK:
how many angels CAN fit on the head of a pin?? - the official IUPAC verdict.

WebElements: the periodic table on the WWW [http://www.webelements.com/]

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