Talk:Periodic table

Ambiguity regarding the positioning of Lanthanum (La) and Actinum (Ac) in the Periodic Table.

Hello! I believe that though we study La and Ac along with the F-block elements, they should be placed in the D-block as they have none and full 4f orbitals respectively. This makes them unfit for being in the F-block. Please do help me with this. Thanks, SSG123 (talk) 17:02, 6 November 2021 (UTC)

That is the so-called "Group 3" problem, discussed at Periodic table#Group 3 and endlessly on these Talk Pages and archives. It will be very difficult to undo the present consensus unless and until IUPAC make a ruling (and many will continue to disagree even then). Mike Turnbull (talk) 21:03, 6 November 2021 (UTC)

Thank You! SSG123 (talk) 06:36, 8 November 2021 (UTC)

There are a couple of things to consider.

1. In 1960, Sanderson (p. 8) wrote:

“If a d electron, for example, can easily behave like an f electron, or vice versa, the argument as to the exact ground state configuration becomes relatively unimportant.”

That is to say, given La is the progenitor of the lanthanides it seems to be the case that it can relatively easily behave as if it were an f element (as is the case with Lu) never mind its electron configuration of 5d¹6s² rather than the expected 4f¹6s².

• Sanderson RT 1960, Chemical Periodicity, Reinhold, New York

2. In any event, if the 4f row is shown as La to Yb, the number of f electrons in each atom corresponds to its position in the row, in all bar three cases (La, Ce and Gd). Whereas if the 4f row is instead shown as Ce to Lu, the number of f electrons in each atom corresponds to its position in the row in only three of 14 cases (Ce, Gd, Yb).

The situation in the 5f row, for Ac to No, is a little more complex, bearing in mind the earlier members show a decreasing resemblance to their transition metal congeners until the group 3 resemblance sets in.

If the actinide series is shown as Ac-No, it can be divided into three relatively cohesive sets:

• Ac and Th, which each have a number of d electrons equal to their position;
• Pa, U and Np, which have a mix of d and f electrons; and
• Pu to No, in which the number of f electrons in each atom corresponds to its position in the row in all cases except for Cm.

The position number and either d or f electron count matches in 10 of 14 cases.

If the actinide series is instead shown as Th–Lr, the three sets become discombobulated:

• Th, the first member, with two d electrons;
• Pa, U, and Np with a number of f electrons corresponding to their position in the row;
• Pu to Lr, in which only Cm and Lr have a corresponding number of f electrons.

The position number and either d or f electron count matches in 5 of 14 cases.

Conclusion: With Lu-Lr in group 3, the electron configuration “filling pattern” becomes easier to explain, and more consistent with quantum mechanics (QM) acknowledging electron configurations do not explain everything and that chemistry is not fully reducible to QM. Sandbh (talk) 10:40, 8 November 2021 (UTC)

Above notes updated. Sandbh (talk) 21:00, 13 December 2021 (UTC)

Error in ionization energy

I spotted a mistake in the section about ionization energy. Ionization energy increases “left to right and down to up”, and not “left to right and up to down” as in the current text 71.232.97.135 (talk) 02:33, 13 December 2021 (UTC)

 Done Yes indeed. I've made the change. Mike Turnbull (talk) 15:28, 22 December 2021 (UTC)

Periodic table of the elements

I’d like to be able to come to this site and be able to see a color coordinated list of the names of them. 135.134.173.151 (talk) 14:52, 22 December 2021 (UTC)

There are many way to color-coordinate the elements and one commonly-used way is shown at Periodic table#Classification of elements. Was there something else you had in mind? Many of the other tables in the article either explicitly name the elements or have links to them which show full names if you hover over them with the cursor. Mike Turnbull (talk) 15:18, 22 December 2021 (UTC)

A black-and-white periodic table image shows its main features best: columns=groups, rows=periods, rectangular units=blocks. Immediately recognisable! Any color coding would distract from this main setup. And after all, this is the introductionary image, no details have to be explained. However, when going into details and analysis, coloring can be very helpful. So there is: 1, 2, 3. -DePiep (talk) 08:32, 9 January 2022 (UTC)

18-column form needed as the lede table

Consistent with what DePiep noted above about a black and white v. coloured table, I suggest the periodic table in the lede should be an 18-column form rather than a 32-column form. The 18-column form is by far and away the iconic form widely recognisable around the world. In comparison, the 32-column form is obscure, non-representative of the literature, and in this context, undue. It should not be featured in the lede although it certainly warrants a mention later on in the article. An 18-column form would also be more legible. Sandbh (talk) 23:01, 9 January 2022 (UTC)

• @Sandbh: no, this is not "Consistent with what DePiep noted above". For starters, I invoke "... would distract from this main setup", "introductionary image, no details have to be explained", "shows its main features best" and "immediately recognisable!". And concluding, I say "[for] details and analysis, coloring can be very helpful" (italics added). -DePiep (talk) 06:49, 10 January 2022 (UTC)
• No. The 18-column format is a deformation, by non-scientific grounds even. We don't need an "iconic" form, we need the informative form. 18-column has a needeless complication: it is deconstructed, a deviation from the proper scientific periodic table. The icon is only helpful for initiated people like scholars (who immediately, intuitively and by excecise, understand and overlook the complications). But tallying published forms is not a sound base to reach a good encyclopedic result: you are polling the in-crowd. Those people are used to it. It started with Seaborg no less 80 years ago, when he needed to fork out the new discoveries as a block (and again, writing for high-end scolars). Scholars more easily could accept the books page-ratio limits (at the cost of extra studies, for example the exact border cases wrt group 3). By the way, since say 2000, webpages are available, overcoming such hard limits.

We are creating a general encyclopedia, and we do not require such proir knowledge, training or intuition. It's easy: After you've seen/grasped/recognised/learned the single-graph version, one can quite easily recognise & understand the forked graph. The opposite route, start by learning the scattered blocks, then reconstruct the full form in mind, is not obvious and requires extra mental steps to get the essence.

As an encyclopedia: there is no advantage in presenting a deconstructed form. -DePiep (talk) 11:00, 10 January 2022 (UTC)

@DePiep: Oh, what I meant by being consistent with you was where you wrote, “And after all, this is the introductionary image.”

Thus, the 18-column form is universally the introductory form in the literature. It matters not at all what your personal views are about how “bad” the 18-column form is. Not only that, the 18-column form has achieved the status of an icon in the Western world. As an encylopedia we are obliged to reflect the literature. Hence the periodic table in the lede should by an 18-column form, as adopted by the International Union of Pure and Applied Chemistry[1], the American Chemical Society[2], the Royal Society of Chemistry[3], PubChem[4], and ptable.com[5]. Sandbh (talk) 09:44, 11 January 2022 (UTC)

I wrote about being an introductionary image in relation to the coloring of details (ie, not useful in this introduction). As one can read. I did not write that being an introduction means there are no encyclopedic requirements. Agree with you that personal opinions don't matter, so it fits that I wrote that for encyclopedic reasons we should use the most helpful one. (Sandbh, next time please leave out the personal jab and the out-of-context misreading—esp when orig quote is nearby so easily to point out. iow: speak for yourself). -DePiep (talk) 15:05, 12 January 2022 (UTC)

I’m not a regular on this article but do have an interest. The main reason the 18 column version is published in so many locations is it’s easier to publish on 8.5x11” or A4 dimensions. It’s a matter of convenience, not preference, in other words. (Let’s just hope we don’t have to make room for the next row, which would likely be 50 columns, anytime soon!) Jtrevor99 (talk) 20:13, 12 January 2022 (UTC)

Mental states with the periodic table

• Understanding and appreciation of the Periodic Table should not require IKEA assembly manuals & skills

Mendeleev, 1871

1871–

Wikipedia reader trying to understand an 18-column periodic table

Early XXI century

Showroom Wikipedia: Featured Article

Periodic Table, 10k visitors per day

DePiep (talk) 20:02, 10 January 2022 (UTC)

Rfc about the periodic table in the lede

Should the periodic table in the lede be an 18-column table or a 32-column table? Sandbh (talk) 04:15, 20 January 2022 (UTC)

Sandbh Why at all do you call for Votes? How does that improve Comments & discussion, as WP:RfC defines & asks for? -DePiep (talk) 05:00, 21 January 2022 (UTC)

• Glossary:

18-column, 32-column: refers to number of table columns that actually contain elements. Not counted are columns with the Period number 1–7, not the placeholder column between group numbers 2 and 3 (often containing * asterisks), and not columns with elements placed below the main table (usually 15+15 elements in 2 rows). It is a graphical, editorial, presentational distinction, and has no scientific meaning or background.

period, group, block versus row, column, rectangle: the first terms are scientific names and have chemical or physical meaning. The second three are parts of the table as such, as 'every' table has. Note: rectangle here is a set of elements visually recognisable as a larger rectangle, following from the predominant empty table space (there are ~four). -DePiep (talk) 08:35, 22 January 2022 (UTC)

!Votes

• 18: Reasons: (1) The 18-column form is by far and away the most common form appearing in books as their lede table (often found on the inside cover); (2) The 18-column form has achieved the status of an icon in the Western world; (3) As an encylopedia we are obliged to reflect the literature; (4) The 18-column form is used by the International Union of Pure and Applied Chemistry[6], the American Chemical Society[7], the Royal Society of Chemistry[8], PubChem[9], and ptable.com[10]. Sandbh (talk) 04:15, 20 January 2022 (UTC)

// Reformated with Sandbh's permission. YBG (talk) 09:28, 21 January 2022 (UTC)

@Sandbh: "most common appearing in books" - by editorial choice and limits such as print page ratio, not by scientific or educational base. No one should have(!) to discover the Periodic table from a crippled form. Today, this being a website we are not limited/forced by bookpage ratio any more, and of course tallying books is no substitute for sound educational approach.

"status of an icon": this is not a museum for old icons. Nor are we tallying preferences (made in another time and context). This is an encyclopedia, aimed to inform. To convey the essence of the Periodic table, for example eh periodicity, the deconstructed 18-column form breaks good encyclopedic presentation. Nice for those in the know, needlessly complicating for those who are here to learn.

"obliged to reflect literature"—but not by copying their editorial choices. Not their page size, not their font type. 18- or 32 column is not a scientific distinction. To be clear: by definition both forms do and should present exactly the same scientific claims.

"IUPAC uses ..."—As we know, IUPAC/Scerri have published recently that IUPAC has not and does not declare preference for any of those two forms.

All in all: we should choose the image that is best for the encyclopedia, in presenting & conveying & education the Periodic table. Tallying old books and non-context situations are not a proper base for this. See also my # !vote for 32 below. -DePiep (talk) 10:31, 22 January 2022 (UTC)

• 18 the 32-column table is too wide to have in the header on a mobile phone. The 18 wide form is fine though I do wish it was made more obvious where the Lantanides and Actinides fitted in rather than people having to look for the gap in the atomic numbers. The presentation forms in the article would be fine with details chopped out. Colours should be used too. NadVolum (talk) 09:39, 20 January 2022 (UTC)

• 18 - appearance on mobi matters to me as NadVolum mentions, and I also think it a better presentation plus better tutorial approach to begin with a simpler colourised version. Cheers Markbassett (talk) 01:04, 21 January 2022 (UTC)

• 32 — Our policy means that we base our content on reliable sources, but we don't have to copy their choices of graphic design. The current 32-column version looks fine on my mobile device; if a reader isn't willing to expend the effort necessary to turn their phone sideways and/or pinch-to-zoom, they won't be getting much out of a science article regardless of its header image. XOR'easter (talk) 20:41, 21 January 2022 (UTC)
• 19 The 32 collumn version needlessly complicates readability, and conveys very little additional information to compensate for this. The 18 column version is frequently used even in scientific coursebooks and the like for this very reason, albeit usually with something to indicate where the two excluded groups belong. I strongly disagree with Easter above that needing to pinch and zoom is an acceptable compromise. Wikipedia needs to be accessible and useable by pretty much anyone. I don't think forcing people to pinch and zoom is an acceptable compromise for being technically slightly more accurate. The 19 column solution suggested below by sandbh would be the best of both worlds. --Licks-rocks (talk) 21:30, 21 January 2022 (UTC)
• 19 per Sandbh Easiest readability of all designs and allows a much cleaner presentation than the needlessly stretched 32 column version. BSMRD (talk) 05:44, 22 January 2022 (UTC)
• 18 and combine all rare earth elements in the column 3. Just listing Lu or La is not a good idea. Same problem with actinides. Putting a 32 column table there gives undue prominence to rare earths. Graeme Bartlett (talk) 07:45, 22 January 2022 (UTC)

• 32 columns, and in black-and-white I add. Per the first of the five Wikipedia pillars: we are writing an encyclopedia. We are to present the infomation accessible for everyone, preventing hindrances in understanding whenever possible. For this, introduction of the Period table by the 32-column graph is ideal. Immediately recognisable and most easy to read, understand and appreciate. Conveys the principles at glance (graph table overview) and when zooming in (element location & context).

TL;DR: being an encyclopedia, we must convey the information as accessible as possible. Nicely, the 32-column graph shows the essence right away from its introduction, both in detail and in glance. And immediately recognisable both as structure and as icon. Then, later on, a Reader more easily recognises or remembers the main structure, further down the road or outside of WP, when a graph shows details/non-primary properties/colors/deformations including 18-columns: all superimposed on the one basic structure, and recognised as such in the mind's background. On the other hand: for readers not familiar with the basic Periodic table structure, the 18-column graph requires mental excercise to replace the cellar-stored elements into their right place, before grasping, understanding and appreciating the Peridic table, while we cannot assume that every reader can do or even understands this requirement. Even worse: the cellar storage distracts from the essence (so gently present in the Right Table: periodicity-with-holes first and foremost). Of course, those already(!) familiar with the Periodic Table like scolars, scientists and editors like us, have studied and internalised the structure beforehand and outside of Wikipedia. Good for them, but not a guide for our encyclopedic presentation. Anyway, 32-column form does no encyclopedic harm to these people: the form serves both groups of readers.

- Longer: We are supposed to clarify matter, and make it understandable. As for the Periodic table, the task of the top image is to convey its principles. All other is distraction, confusion, mis-aiming. That core is: the plain flat 2-dimensional Table. Principal features: rows/periods, columns/groups, blanks/blocks full stop. Not by accident, these are present and immediately recognisable in a b/w 32-column form. Even better: this without distractions.

- Shifting parts to the cellar makes the table's essences hard if not impossible to grasp. It would require(!) a mental excercise to reposition the cellar-stored parts back in their right place. It is as if an uninitiated reader has to apply an IKEA montage manual each time(!) one meets a deconstructed 18-column Periodic table. That is: each and every time before being able to get to whatever aspect the reader is looking for.

Seaborg in his lab

Hubbard Periodic table (1924–..)

- For the initiated reader, those who already have internalised the main structure, there is no loss or harm (unless one counts "I am not used to it", but allow me to discharge this as not an argument). Like scolars, scientists, interested readers. There is no reason to cater only just for those (with a complicated graph) while the broader all-reader inclusive approach is available. Even worse: it would be counterproductive to take those readers as leading for the encyclopedic presentation. Our encyclopedia job is to write for people who do not (yet) know.

- Now once the basic, 2-dimensional straight Table is introduced and recognised (that is, in 32-column graph), a reader can dive into detail graphs such as those presenting electron configuration, classifications, a metalloid staircase, physics, without loosing the big picture = structure. Which is the perfect way to present complicated information: unfold, zoom in, invite to details; all from the Big Picture. This fits with how the human mind works in learning.

- Coming from a straight Periodic table, other graphs are more easily understood (again, for not having to bother with the mental mis-image): presentation forms (like earlier Mendeleevian tables, spirals) and different structure by science (Janet's Left Step, ADOMAH's quantum based)

- Illustration. Seaborg was scientist who, in the period 1930–1960, made huge contributions to the science of elements & the Periodic table. He was the one who discovered the f-block elements structure, and they were conveniently put below the then-known Periodic table (introducing placeholder notation like * asterisks). While doing so, Seaborg did not need an introduction to the Periodic table: he rewrote the Table himself, and from an already internalisation into intuition. On his laboratory wall was Hubbard's Periodic table wallplate. Hubbard's Table was complete, but not an invitation to study the topic. For the initiated Seaborg this was no issue. For readers of an encyclopedia, looking for an inviting introduction, this would be prohibitive in appreciating the Periodic table.

-DePiep (talk) 08:01, 22 January 2022 (UTC)

• 19. This is what appears in most sources. Yes it requires a little bit of mental effort to put the footnote back in, but the reader is going to have to do that when reading the literature anyway, so we should not hide that. I note that the first section already builds up the PT first with 32 columns and then explains the footnote, so if you read the whole article, you'll figure out what's going on too. Double sharp (talk) 10:16, 22 January 2022 (UTC)

Talk, notes, questions, suggestions

@NadVolum: The location of the lanthanides and actinides could be be made obvious by adding a column for them, as seem in the image. I feel that colors is something that should be the topic of a separate RFC, after this one. Sandbh (talk) 22:58, 20 January 2022 (UTC)

Conventional periodic table showing where the Ln and An fit in

I certainly much prefer that! Thanks. NadVolum (talk) 16:52, 21 January 2022 (UTC)

Graphic design
I feel that 18 or 32 is not primarily a graphic design question. Rather, it has more to do with the fact that there are only 18 numbered groups, not 32.

Another consideration is that the early actinides show some similarities to their transition metal congeners:

Lu +3, Hf +4, Ta +5, W +6, Re +7, Os +8
Ac +3, Th +4, Pa +5, U +6, Np +7, Pu +8

This secondary alignment is not apparent in the 32-column form.

Further, there is a corollary between the lanthanides and d block metals extending to the similarities of La with Lu; Ce with Zr/Th [11]; and the recent preparation of Pr(V) cf. Ta(V).[12][13] Sandbh (talk) 03:46, 22 January 2022 (UTC)

Prerequisite for this RfC question is, that there is no scientific difference between those two graphical (editorial, presentational) forms. And I don't see how one could wiggle in these scientific differences (in an RfC you wrote yourself btw). So no, this is *not* part of the discussion or proposals.

Already Eric Scerri et al. (2020) for IUPAC have declared that the presentation form between these 18/32 is a free choice, i.e., has no scientific meaning.

Just a small thing, but the font used in that 19 column form above could be made a bit larger to fit the cells more like they are in the current 32 bit form. Then the actual contents would be quite easily readable on a mobile without enlarging I think. NadVolum (talk) 09:58, 22 January 2022 (UTC)

References