
Alternative Periodic Tables - bluesmoon
https://en.wikipedia.org/wiki/Alternative_periodic_tables
======
will_brown
I was recently reading this article along with electron shell/sub shell
articles specifically for the purpose of learning about alternative
representations.

My real interest is in alternative representations of the 4 cube/hyper
cube/Tesseract.

All I can really find are the commonly accepted representation as seen here:
[https://en.m.wikipedia.org/wiki/Tesseract](https://en.m.wikipedia.org/wiki/Tesseract)

And Hinton’s colored cubes: [https://higherspace.wordpress.com/tag/hintons-
cubes/](https://higherspace.wordpress.com/tag/hintons-cubes/)

If anyone can link any other alternatives.

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XaspR8d
I always found it strange that the standard view usually depicts Lanthanum +
Actinium on the main block and Lutetium + Lawrencium on the auxiliary. I
suppose historically it makes sense that valence was the motivating factor,
but at my (totally layperson at this point) glance, the pedagogy seems like it
would be simpler to just adopt a more electron-orbital-focused design like the
"left step" one.

In any case, it's not like anyone should really be looking at the table
placement of an element say to themselves "ah yes now I know everything about
how this behaves"; the exceptions are basically an intractable necessity in
chemistry.

~~~
jcranmer
Lanthanum + Actinium actually do have the electron configuration you'd expect
for a leftmost d block element--their third electron goes into the d block
instead of the f block.

In practice, the period 6 and 7 elements have quite a few violations of the
Afbau principle, and some predictions of period 8 predict some truly anomalous
things for electron configuration (e.g., let's start filling up the 9s/p
shells before the 8p shell is finished).

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timthorn
If you're in Cambridge, there's an exhibition of alternative periodic tables
on until Friday at St Catherine's: [https://www.cam.ac.uk/news/exhibition-
marks-the-150th-annive...](https://www.cam.ac.uk/news/exhibition-marks-
the-150th-anniversary-of-the-periodic-table)

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Balgair
Another 'fun' thing to go through is the _naming_ of the various elements, and
some of the elements that were named, but turned out to be other elements
already (Canadium, for example).

Tom Scott has a great video on how Ytterby, Sweden managed to get four (!)
elements named after it :
[https://www.youtube.com/watch?v=l6lGe5jgZgI](https://www.youtube.com/watch?v=l6lGe5jgZgI)

More on the naming of the elements here:

[https://www.carolina.com/teacher-
resources/Interactive/namin...](https://www.carolina.com/teacher-
resources/Interactive/naming-the-elements/tr28303.tr)

[https://books.google.com/books?id=Ck9jBAAAQBAJ&pg=PA223&lpg=...](https://books.google.com/books?id=Ck9jBAAAQBAJ&pg=PA223&lpg=PA223&dq=canandium+wiki&source=bl&ots=D0iomr5Qe0&sig=ACfU3U25eqT1F2eZg-
XPNdukJmCnyGG68w&hl=en&sa=X&ved=2ahUKEwiskuyl_rHhAhVCbKwKHWPnC4MQ6AEwC3oECAcQAQ#v=onepage&q=canandium%20wiki&f=false)

~~~
jcranmer
> how Ytterby, Sweden managed to get four (!) elements named after it

Those four elements are yttrium, erbium, terbium, and ytterbium. The short
answer as to how a small village could get so many elements named after it is
that rare earth elements are so difficult to separate from each other. So the
compound that was thought to be yttrium was actually a mixture of several of
them. (Cerium provided the other group of rare earths--this eventually
resulted in didymium, which was considered an element for a few decades until
people realized it was actually a mixture of praseodymium and neodymium).
Terbium and erbium were the second and third elements found from yttrium.

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Aardwolf
What a coincidence, I stumbled upon this page very recently!

I like the left-step one actually, it makes so much sense, more than the
standard one in fact I would say (but I'm not a chemist though)

~~~
jcranmer
The left-step one actually disguises a few important facts from the normal
periodic table.

The obvious one is that He (which is only a full s shell) is _far_ more
similar to elements with full p shells than those with only a full s shell. In
terms of bonding, the outermost s and p shell influences bonding the most. He,
who has no p shell, acts far more like an element that has a full p shell than
an element that only has a full s shell and an empty p shell because of the
influence of the p shell on bonding, so you do want to stick He in the same
group as Ne, Ar, Kr, Xe, and Rn.

The other thing that is tricky is where the f block starts to integrate in the
table. The f shell of electrons is far less involved in bonding and observable
effects than the d shell is. Furthermore, even the basic electron
configuration breaks down because the f and d blocks are so similar in energy.
La and Ac both fill their first d electron before the f electron, and several
actinides actually retain this single outermost d electron rather than dumping
everything in the f block. There is some dispute as to whether or not you
should put La/Ac in the d block, or Lu/Lr in the d block, or instead put the
entire La-Lu/Ac-Lr block in that one-element hole (this is perhaps one of the
reasons why people like using the short form a lot--you can be somewhat vague
here).

~~~
madcaptenor
I haven't thought about chemistry in a while, but He as an alkaline earth
metal just makes me laugh.

(I have seen layouts where H is above F, though, and I can get behind that...)

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ionforce
Is there a name for this field? I guess it is all rate limited by the amount
of data that can be categorized and visualized in this way, which feels very
specific. But I love it.

~~~
mimixco
A taxonomy. See Edward Tufte if you like this stuff.

