Talk:Periodic table/Archive 7

Issues in the Bohr model
The article states: in the Bohr model, atoms with a higher number than 137 are problematic because their outermost electrons would have to travel faster than light.

The Bohr model, now obsolete, was so successful that you can still find it in school books, at least around 2000 when I was in secondary school. However, one book also mentioned the concept of the electron orbiting its nucleus to be outdated. Does that mean that the problems with atoms with numbers above 137 are no longer expected to occur? Steinbach (talk) 20:04, 13 June 2014 (UTC)
 * It's not that simple, because the theories that have replaced the Bohr model, such as non-relativistic Schrodinger quantum mechanics, also have problems above 137. Dirac66 (talk) 21:02, 13 June 2014 (UTC)
 * Well, the article actually mentions the relativistic Dirac equation. But to be sure, problems with newer models don't include electrons having to run faster than light? Steinbach (talk) 00:13, 14 June 2014 (UTC)
 * No, but other relativistic effects occur as the electron velocity approaches the speed of light. For one thing the electron mass increases as v → c. Dirac66 (talk) 00:51, 14 June 2014 (UTC)

Merger with Periodic table (large version)
At present, Periodic table (large version) consists almost entirely in a short interactive table in the form of the periodic table. It attained featured list status back in 2005, but standards for what constitutes a featured list have risen significantly since then. I doubt that the list would pass a featured list review in 2014, and I don't see a way of improving the article so that it would pass. Furthermore, "Periodic table (large version)" doesn't seem like an appropriate subject for an entire article to me; it's more an infographic than an article. This entire "large" version of the periodic table is so short that it would fit comfortably at the bottom of the "Layout" section of this article. For these reasons, I recommend that Periodic table (large version) be merged here. Neelix (talk) 22:04, 24 July 2014 (UTC)
 * Notified WP:ELEMENTS . -DePiep (talk) 00:36, 25 July 2014 (UTC)
 * The same page is proposed for deletion at this AfD. Procedural confusion to me. -DePiep (talk) 19:01, 28 July 2014 (UTC)


 * Support. I agree that the separate existence of Periodic table (large version) is absolutely useless. Perhaps that is why I never noticed it before. Dirac66 (talk) 22:40, 24 July 2014 (UTC)


 * I Object, it's not that simple. The quest in itself is OK.
 * First some questions. What would that merge look like? The huge large P.T. into article periodic table, really? That P.T. is unlimited by intention (There are even more of these with reason).
 * Let me speak about the large table page (I have worked on a lot). I don't mind its FA-status being re-evaluated (though the table has improved greatly last years, I can say myself ;;-) ). As for the existence and the need for this article
 * 1 A "large periodic table", read: having cells large enough to cover the major information, unrestricted by webpage screen size. So the table format & layout serves a purpose for this reason. Like one that covers the wall in a science-classroom. I say this is an encyclopedic need.
 * 2 - OK then, but why an article? That is because WP does not allow a page to be solely a template (however useful that template in itself is). So, if we cut out the surrounding article text, there would be left a sole template - oops, speedy deletion of the article. Next day: the template itself is gone for being unused. That's the domino fall by WP logic.
 * The good news is that this is a 2005 logic (as was the FL award). I sketch: if we can find a reason to keep large cell periodic tables in mainspace, I'll go with that. I don't want to depend on IAR (IA2005R that is) exceptions. I expect wikilawyering. -DePiep (talk) 23:06, 24 July 2014 (UTC)


 * I appreciate you engaging with this discussion, DePiep. I have read through your comments, but I don't see your reasoning behind opposing the merger. If I am understanding you correctly, you want the large periodic table to be kept, and you provide reasons for keeping it. I agree that it should be kept, and am arguing that it be relocated to a subsection of the main Periodic table article. You asked what the merger would look like. What I have proposed is to include it at the end of the "Layout" section. Perhaps the confusion between us would be clarified if you explained what you mean by the statement that "it's not that simple". As far as I understand, the "large" periodic table, which is already a template, could easily be moved to this article by transcluding it here rather than on its own article. What are your thoughts? Neelix (talk) 13:18, 25 July 2014 (UTC)
 * Yes I want it to be kept, main point. And available to the reader (so in content space). Your detail of having the this big, out-of-pagesize template in the article I did not yet address. Some notes first: when it is in the article, it usually shows up with a horizontal slider bar. And it is quite high, so there might be a hide/show botton added (not advisable in content space). Then there is also the 32-column bit table 32 columns, large cells, another worthy variant. So the variance is in the graphic (18 vs. 32 columns) and in the detailing (info per element).
 * In short, I don't see how the big table could survive in article periodic table. The graphic 18/32 variants by big cells is way too fringe for this page. For content, it may be seen as mostly a repetition of the more compact in-screen P.T already there (twice?). Just with some more detail per cell. So, when the big table is in this article, I fear some generally interested editor (or a learning/wikilawyering one; as is happening today in a nearby area) will come along and say: "too much repetition, remove it or hand in your FA star". From that moment, I am not sure what will happen. I've been having to defend sound encyclopedic and wikiapedic situations way too often to trust the outcome. So I first want to hear a strong conclusion that by wikipedia guidelines & intention such a merge is to stay. About the encyclopedic base for large tables in itself, I have less fear. -DePiep (talk) 23:10, 25 July 2014 (UTC)


 * I object as well.
 * The merger would be not great. Suppose we had a table just like the one we discuss, but it was written in Chinese hieroglyphs. Then someone stumbles upon it, thinks it should not be a separate page anymore, and suggests so. It would be clear why it would not be okay to move that table to this article: it is not relevant. Same applies for the discussed table: this is certainly not the place to keep it. On the periodic table page, there is no need to keep the detailed page, the article is just an overview one, and the table we have is just enough. Details belong elsewhere. So, whether the periodic table (large version) page will be deleted/redirected or not, this is not where the large table should end up.
 * Keep it or delete it? As for me, I lean towards keep (would not die if we deleted it, though) for the reason DePiep mentioned, I couldn't add any more.--R8R (talk) 22:45, 25 July 2014 (UTC)


 * Procedural note: The same page is proposed for deletion at this AfD. -DePiep (talk) 19:01, 28 July 2014 (UTC)
 * Procedural note: This merger discussion appears to have ended having established that consensus is against the merger. If you are interested in discussing the potential deletion of the Periodic table (large version) article, you are welcome to participate in the AfD linked by DePiep above. Neelix (talk) 17:23, 29 July 2014 (UTC)
 * I do not understand. "appears to have ended"? What happened with the arguments & ideas & questions then? I maintain my point that the process is broken. -DePiep (talk) 21:23, 29 July 2014 (UTC)
 * I was the nominator of the merger. Surely I can withdraw my nomination. Neelix (talk) 14:40, 30 July 2014 (UTC)

Large periodic tables - overview

 * This is an overview only, and may be refined over time. In itself it is not up for discussion. -DePiep (talk) 00:12, 25 July 2014 (UTC)

A reduced version of the periodic tables documentation overview:

Semi-protected edit request on 24 July 2014
The text "Elements are presented in order of increasing atomic number" is ambiguous. It should say something like, "Elements are presented in order of increasing atomic number (by row starting at the top, within each row starting on the left).  The atomic number is listed at the top of each element box. "

BenjaminGSlade (talk) 18:34, 24 July 2014 (UTC)
 * Isn't that too specific? It follows English writing & reading direction: start top-left, at end of line (right) continu at next line, left side, and continue reading &tc. A note could be needed in the Arabic site, but not here imo. -DePiep (talk) 20:59, 24 July 2014 (UTC)
 * Perhaps the second suggested sentence would be more useful than the first. A beginner might not realize that those integers are the atomic numbers. Once that is made clear, any reader can follow the sequence of numbers. And in any case the words by row starting at the top are misleading when we arrive at the rare earths, whose location will be mysterious without still further explanation.Dirac66 (talk) 00:50, 25 July 2014 (UTC)
 * 'Second sentence'? I don't understand. Please quote something. -DePiep (talk) 00:57, 25 July 2014 (UTC)
 * Agree with That would fulfill all the concerns it seems, and explain enough but not too much to confuse the novice reader. Add / change to "The atomic number is listed at the top of each element box"  Mlpearc  ( open channel ) 11:21, 25 July 2014 (UTC)
 * Yes, the second sentence, which I would add, is "The atomic number is listed at the top of each element box." The first sentence, which I would not add, is ""Elements are presented in order of increasing atomic number (by row starting at the top, within each row starting on the left)." Dirac66 (talk) 14:23, 25 July 2014 (UTC)
 * It's not essential that the atomic number be listed at the top of each box (eg), though it happens to be that way in our examples. How about this version, which also moves the explanation of "atomic number" to the first use of that term?  I'm not sure whether "chemical symbol" is the best term for the standard elemental abbreviations.  Adrian J. Hunter(talk•contribs) 13:07, 27 July 2014 (UTC)
 * - The easiest point: they are not abbreviations, they are symbols ;-). I remember a discussion that "chemical symbol" was the best (non-ambiguous in enwiki) term we could find.
 * - Repositioning the atomic number in the cell can be done, of course. Note that this shold be applied to all our PT cells where applicable, all larger ones (For unity of PT presentation over enwiki). And I like the this-link Adrian J. Hunter gives, because it puts the number near left-below the symbol, where it formally is written: 9F. OTOH, that would make the OP moot, isn't it? I mean to say, when the number is in line with other letters&numbers (the symbols), the ascending pattern is not presented to the eye by glancing (it takes a mental search to separate: by reading).
 * - For now, my opposition to the OP proposal is maintained for reasons mentioned. -DePiep (talk) 18:56, 28 July 2014 (UTC)
 * Red information icon with gradient background.svg Not done for now: No consensus for change -- Mdann 52   talk to me!  08:15, 7 August 2014 (UTC)

Electron configuration
ref: C Moore, Atomic Energy Levels, Vol 1, US Bureau of Standards, 1949

R. Portela F. (talk) 21:33, 2 September 2014 (UTC)

Suggested for you guys, a hug.
Periodic table

Click on the elements in Periodic table Adobe Reader and download.

See also: Periodic table Adobe Reader

--User:R. Portela F. 13:25, 4 September 2014 (UTC)
 * Hi . Can you write more about what you want to say? The enthousiasm looks great, but there could be other things in your posts that I am missing. Thanks. -DePiep (talk) 21:36, 4 September 2014 (UTC)

Metal-metalloid-nonmetal section
In section Periodic_table I've made some edits too. I changed its title, because "Categorisation" is not a universal term in this (we use it in enwiki because it nicely has a single meaning, other than say 'series'). I also added a new image that shows the three major categories in the PT. Improvements may well be possible or even needed. -DePiep (talk) 14:35, 18 September 2014 (UTC)

Overview & layout
I have changed the section title 'Layout' into 'Overview'. I think right after the lede, we should describe the main characteristics, not the graphical intricacies. Also, I want to tear away the graphical options from the structural variants (aka alternative periodic tables, or variants).

I started putting those graphic issues (mainly 18 vs. 32 column, but there is more) in a single subsection. This way, we don't have to explain the issue in every section.

But I have not nice solution for the next questions. Any ideas? -DePiep (talk) 11:42, 18 September 2014 (UTC)
 * 1) Maybe the graphic points are not important enough to be in section #2. After all, the structural background (group, period) is what the PT is about. Is there a natural, lower position for this section?
 * 2) Somehow we need to add a link like "See section #Alternative structures". Any good practice for such an in-page link?
 * 3) We could note Mendeleev's 8-group PT in this graphics section, as a background. But only in a few words then, I think he can be described in the History and Alternative structures sections.
 * 4) About #Open controversies. I have not found a way to describe these element-level issues in this graphic section (like "Placement of hydrogen and helium", and "Period 6 and 7 elements in group 3"). Shall we use these sentences: "Within a given layout, helium can be placed in group 18 or in group 2", and "Within a given layout, there can be variants like Sc/Y/Lu/Lr vs. Sc/Y/La/Ac"?
 * About that opening section 'Overview'. As it is now, it has 2/3 paragraphs about the heavy elements (situation today, discovery). Let me propose that we move those (mostly) to a section in 'History' (with subsection title: 'Today' ;-) ), where developments & timelines are a natural way of describing. Also, the 'Overview' section could use more basic notes about, say, groups/columns and periods/rows structure as the basic periodicity. ping. -DePiep (talk) 11:56, 18 September 2014 (UTC)
 * ping (how do you ping all the WP:ELEM members?)
 * I have read this post; this is a placeholder that will be replaced by a reply once I think I've finished mulling over it. Double sharp (talk) 15:16, 18 September 2014 (UTC)

Groupings -Classification into metals, metalloids and nonmetals
Reading through the recent edits I noticed these statements which over-simplify the situation- "Metals are ordinarily shiny, highly conducting solids which form alloys with one another and salt-like ionic compounds with nonmetals. Nonmetals are mostly coloured or colourless insulating gases that form covalent compounds with one another." Ummm. Metals do not form salt-like compounds with the non-metals that are the noble gases. The only reactive non-metals which are gases are nitrogen, oxygen, chlorine and fluorine. The rest are solids or in the case of bromine a liquid. I am still up to my neck in other commitments so I am afraid I cannot make the necessary tweak.Axiosaurus (talk) 18:14, 19 September 2014 (UTC)
 * These texts were not edited yesterday ;-). And I too had a question marks about them. A first thought was: what would we loose if we deleted them completely? The three categories are mentioned and linked already. However, we could use a sentence that describes not what a metal is, but why metal-nonmetal is important for the periodic table. -DePiep (talk) 19:23, 19 September 2014 (UTC)
 * Fixed with some copy-editing. Sandbh (talk) 23:29, 19 September 2014 (UTC)
 * We are still claiming that Nonmetals are mostly ... gases. Actually, of the 17 elements shown as nonmetals in the Image Metals, metalloids and nonmetals in the periodic table, only 11 are gases at 298 K and 1 atm. I think that six exceptions (C, P, S, Se, Br, I) are too many to say mostly - it would be better to say The majority of nonmetals are ... gases. Dirac66 (talk) 02:23, 20 September 2014 (UTC)
 * OK, one more time then :) Sandbh (talk) 05:19, 20 September 2014 (UTC)

Can someone qualified evaluate adding a periodic table here ?
Am not expert in editing Wikipedia nor on the subject; but it has resided in my favorite links many years and just found out it is not mentioned in the main article page :
 * http://www.perfectperiodictable.com/

75.227.64.209 (talk) 20:00, 28 November 2014 (UTC)MB-28Nov2014-Externet


 * This article here is about the standard layout. But we do have a separate Alternative periodic tables article for other options. Is Alternative periodic tables what you want? DMacks (talk) 20:09, 28 November 2014 (UTC)

Please, do something about Barium
Please, if possible, edit the Periodic table shown under the contents. In its natural form, Barium is a liquid, not a solid, and its atomic number should therefore be green, not black, which further confuses things. Please next time have a professional chemist go over/write articles related to the elements and chemistry. Please take this under consideration.

Minecraftwizard (talk) 03:47, 3 December 2014 (UTC)
 * We will, when it starts making sense. Meanwhile, read through barium and other related articles. Materialscientist (talk) 03:56, 3 December 2014 (UTC)
 * Barium melts at 727 °C... Double sharp (talk) 03:59, 3 December 2014 (UTC)
 * Perhaps the editor has confused barium the element with the liquid "barium" you take when having an x-ray examination of your GI tract. Sandbh (talk) 09:23, 3 December 2014 (UTC)

Semi-protected edit request on 28 December 2014
Please change 1 to 119

117.201.23.241 (talk) 01:58, 28 December 2014 (UTC)
 * Not until another element (probably 119 or 120) has been discovered and the discovery has been reported by reliable sources. Double sharp (talk) 03:40, 28 December 2014 (UTC)
 * To 117.201.23.241: This is a long article. Please identify the exact sentence which you think needs changing. Perhaps Double Sharp did not understand where the change should be made - I certainly do not understand where.Dirac66 (talk) 04:23, 28 December 2014 (UTC)
 * I took what I imagined to be the most plausible interpretation, as the article's usage of "1" is mostly for the group or period, where the number 119 makes even less sense. As an atomic number, as in the lede, it would make some sense. But you're right – this request isn't very clear... Double sharp (talk) 12:10, 28 December 2014 (UTC)

Which brings up an interesting idea
The [Talk:Periodic table#Please, do something about Barium|above]] request makes me think of a really neat novelty PT -- just Z+Sym and below the PT a widget to adjust standard conditions. The widget could be a slider bar (or two) showing the temperature (and maybe pressure), or just a set of radio buttons with the names of various locations. When the widgets are changed, the symbols would change color to indicate the physical state of the element in the adjusted standard conditions. It would go a long way to increasing the accessibility and usability of WP to others. Unfortunately, we probably don't have enough information about the 'primordialness' of various elements elsewhere in the universe, but that deficiency might be just enough to encourage someone to sign up and start editing. YBG (talk) 16:07, 3 December 2014 (UTC)
 * But ... other intelligent life of course will have discovered the Elementary Periodicity, and so will have a headache/solution for the suggestion of periodicity in this one. YBG, can you compose a sequence message, to help them out? -DePiep (talk) 16:57, 3 December 2014 (UTC)
 * Such composition skills are pretty weak here in YBG-land -- and the visual arts aren't any better. YBG (talk) 03:40, 4 December 2014 (UTC)
 * No one currently has access to sources for other civilizations' formulations of the periodic table, so they could not be in the article yet. ;-) However, I really like the idea of sliders to adjust temperature and pressure – they let you present melting and boiling points without cluttering the table.
 * As for "primordialness": H–Mo, Ru–Nd, Sm–Bi, Th, and U must be primordial. These are all stable, or their longest-lived isotope has a half-life comparable to the age of the universe (209Bi, 1 billion times the age of the universe; 232Th, approximately the age of the universe; 238U, about 30% of the age of the universe). The others would depend on how recently their system formed after the supernovae created some of pretty much every nuclide. (If their system is old enough, primordial 244Pu – half-life about 0.6% the age of the universe – might not be present in large enough quantities there to be detected, although it just barely is on Earth!) Double sharp (talk) 13:28, 4 December 2014 (UTC)
 * I have no idea how one would go about implementing the sliders ... It would be very difficult to have enough data to support two sliders (temperature and pressure). But a single temp slider would only require two data points (BP+MP) per element.  But it would be much easier to have radio buttons for some select locations -- say each of the nine eight planets, the sun, deep space, and maybe a couple of really extreme locations.  But then that opens up another wrinkle.  Anybody wanna place odds on whether we could decide on the appropriate color for the fourth state of matter in less than 420 days?  YBG (talk) 06:41, 5 December 2014 (UTC)
 * All we need are a set of phase diagrams! :-) Naturally, the rare radioactives would get (unknown).
 * The only primary colour left is blue, so we might as well use that for plasmas. But you would need really high temperatures for that colour to be useful.
 * Do you want the sun's surface, or the core? The core would make a fairly homogeneous but also not very interesting periodic table. The surface would make everything gaseous (or maybe plasma? I'm not sure) except W and Re which are still liquids – W b.p. 6203 K (5930 °C, 10706 °F), Re b.p. 5903 K (5630 °C, 10166 °F). I mentioned the Fahrenheit values because I'm pretty sure these are some of the only really useful appearances of five-digit Fahrenheit values. Double sharp (talk) 08:03, 5 December 2014 (UTC)


 * OK, I've really got too much time on my hands. Here's a start at collecting the data.  All of the data is ripped off from elsewhere in WP.  For the planetary data, I used the surface temperatures, using a separate columns for the mercurial day and night.  For the elemental data, I stripped off the references and the other extraneous columns.  I suspect there are a bunch of errors, so please feel free to correct it.

Heavenly bodies

 * Cheers! YBG (talk) 09:28, 5 December 2014 (UTC)

Re heavenly bodies
I've made some corrections and, to facilitate checking, added extra rows at the end with pseudo-elements whose MP or BP is equal to the each temperature. I verified the "Solid" entries by sorting on MP and then searching for "Solid" so it is highlighted everywhere. Similarly, I verified the "Gas" entries by sorting by BP and searching for "Gas". Try it, you can see how the errors jumped right out! I'm pretty confident the "Solid" and "Gas" entries are all OK. The "Liquid" and unknown ("-") entries still need to be verified. YBG (talk) 10:38, 5 December 2014 (UTC)
 * I have seen no slider at WP working this way. It could be made into a gif animation (one image per planet/sun). Nice to know that Rf is liquid on the sun ;-) . -DePiep (talk) 10:42, 5 December 2014 (UTC)
 * &lt;funny notes>Amusing: Mercury symbol.svg at Mercury symbol.svg. &lt;/funny notes> -DePiep (talk) 11:16, 5 December 2014 (UTC)


 * It looks like some of the data here doesn't correspond with the articles – the W article gives boiling point 6203 K, but here it is 5828 K, for example. Double sharp (talk) 01:22, 6 December 2014 (UTC)


 * Yea, I noticed that myself; I decided to ignore the articles and just use the data from #Planets in List of gravitationally rounded objects of the Solar System. For example, in that chart, the mean surface temp of Mercury symbol.svg is listed as "440–100", but in Mercury (planet), it says "ranging from 100K at night to 700K during the day at some equatorial regions" -- and then the infobox has SIX different temps: a min, mean and max at two different locations.  That discrepancy can easily be explained due to Mercury's great variation; I suspect that the other locations probably have similar explanations if you dig a bit differently.  If there are any discrepancies we can't easily explain, we could ping them over at WP:Astronomy.  Let them mess with their Mercury symbol.svg, and we'll mess with our Mercury symbol.svg. YBG (talk) 03:48, 6 December 2014 (UTC)


 * And about the slider -- yea, I'm not sure there's a way to have interactive widgets in WP; I think sortable tables is as interactive as it gets (though I suppose editing is pretty interactive). Anyway, I think the best way to do it is to make a version of Element cell that takes a temperature parameter, then make a version of Periodic table that also takes a temperature parameter and passes it along to the each individual cell.  Finally, make a page that displays multiple versions of the PT.  Now if there was just a way to make it so that only one version was showing at a time. YBG (talk) 04:17, 6 December 2014 (UTC)


 * Perhaps a gif that shows the periodic table, looping from 0 K to around 6250 K? To be clearer the phase colour can be a background colour, so that the cell size can be reduced even further. Double sharp (talk) 15:27, 6 December 2014 (UTC)

There's a temperature slider that indicates solid/liquid/gas phase for the elements at http://www.ptable.com/#Writeup/Wikipedia using normal (1 atm) boiling and melting points. As for the planets, I wouldn't even pretend to do anything for gas giants. Well-defined mean surface temperatures and pressures are meaningless there, so the data would be meaningless. For the inner planets, Double Sharp's comment about phase diagrams is apt. For example, the table above shows sulfur as a gas on Venus using melting and boiling points at 1 atm, but a quick googling of the phase diagram for sulfur shows that sulfur would actually be a liquid on Venus because of the high pressure (~92 atm). A single periodic table using mean T and P for us and our nearest neighbors showing the state of elements on Venus, Earth, and Mars is definitely doable. As for Mercury (the planet), liquids could never exist there because the almost total lack of pressure is below the triple point of any element. Whether certain solid elements would sublimate at Mercury's T and P is tricky and interesting. Extending the Clausius Clapeyron equation (or a graphical equivalent like the ones at and ) down to the 10^-15 atm value that's cited by NASA at  would give answers for the temperatures on the hot and cold sides. But the hot and cold sides probably have different pressures also due to the differing impact of solar weather on the teensy amount of pressure. The time required for sublimation of a rock-sized solid or even a solid the size of a grain of sand to take place in a closed container at Mercury's T and P might be greater than a lifetime (I don't know.), so Mercury data might also mislead the reader about what would actually happen. I hope someone considers creating a Venus/Earth/Mars table. A single table could indicate the small number of elements that would be different on each planet. I haven't seen it before Flying Jazz (talk) 23:01, 10 April 2015 (UTC)
 * This is very cool. Thank you for posting it. YBG (talk) 05:02, 11 April 2015 (UTC)

Mahusha
Please take into the note that why this article does not have explanation about 'modern periodic law''.
 * The above unsigned comment was added by at 10:40 am, 18 March 2015, Wednesday (UTC). A minute later, it was signed by ; then nine minutes after that, the signature was first reformatted and then deleted by the original editor. YBG (talk) 06:09, 11 April 2015 (UTC)
 * I believe you are referring to the fact that originally the elements were arranged by atomic mass but later the atomic number proved to better predict periodic trends. YBG (talk) 06:09, 11 April 2015 (UTC)

Po: atomic weight
see, question by IP: "What is the atomic weight of polonium? Is it (209) or (210) as indicated periodic table?" (copy/pasted here -DePiep (talk) 18:30, 21 February 2015 (UTC))
 * Per Isotopes of polonium, 210 is the longest-lived isotope known, but 209 is longest-lived among naturally-occurring ones. What are some wikipedia pages/templates that have the full table (with masses), and what do they say about the meaning of values being in parenthesis? DMacks (talk) 20:38, 21 February 2015 (UTC)
 * Let me notify the IP: . -DePiep (talk) 20:47, 21 February 2015 (UTC)
 * I think you've misread the table at isotopes of polonium. The half-life of 209Po is listed in "a", that is years; so its half-life is just over a century and a quarter. However the half-life of 210Po is listed in "d", so its half-life is only about four and a half months! So 209Po is the longest-lived isotope known and thus the value listed in the PT should be "[209]". Double sharp (talk) 08:27, 30 March 2015 (UTC)
 * I suppose it is an SI convention to use 'a' for 'annum', so we probably can't use 'y' even though this is en.wikipedia.org not la.wikipedia.org. At the very least, it should be wikilinked or marked with abbr. YBG (talk) 01:42, 31 March 2015 (UTC)


 * *gah* yeah, bad misreading. And worse, "d" and "a" look not-very-distinct on several of my monitors too:( DMacks (talk) 03:10, 31 March 2015 (UTC)
 * Wonder if these tables can be made sortable. So one could order by halflife or decay-mode, for example. DMacks (talk) 03:13, 31 March 2015 (UTC)
 * Sorting can be done, but it won't be real easy. Check out Help:Sorting. Seems to me that the sort key should first be the unit of measure in magnitude order, then the number. I can think of some of the almost limitless ways to do it. Probably worth thinking about and then coming up with a straw man to discuss. YBG (talk) 03:53, 31 March 2015 (UTC)
 * Some of the "Isotopes of..." data tables are just plain text, while others use a the val template. I'm working on improving or wrapping that to generate a sort-key automatically. We'd only have to pass a parameter saying what unit to use (arbitrarily choosing among seconds, days, years, etc) and all values would be compared for purposes of sorting via conversion to that unified unit. DMacks (talk) 13:27, 31 March 2015 (UTC)
 * The unified unit should be the second which is the recognized SI unit of time. Long half-lives in years are often converted to seconds, but no one converts short half-lives in seconds to years (or nanoyears).
 * And I don't see the atomic weight of Po on the tables in this article, either 209 or 210. Perhaps the IP was referring to a printed periodic table in some book? Dirac66 (talk) 14:00, 31 March 2015 (UTC)
 * I hope long half-lives will be displayed in common time units like days or years and not in not in ks, Ms, or Gs. YBG (talk) 15:48, 31 March 2015 (UTC)
 * The whole context here is how to handle them in a consistent hidden detail for purposes of sorting, and it therefore makes no difference (within the limit of wiki's math precision) which one that is, and which is also unrelated to whatever units are best for each entry's display. DMacks (talk) 16:32, 31 March 2015 (UTC)

Thanks for the clarification. I gather that you are thinking of a form like one of these:
 * 1.
 * 2.

Another alternative to consider is this one
 * 3.

where the following notation is used:
 *  : y, d, h, min, s, ms, µs, ns
 *  : year, day, hour, minute, second, …
 *  : 4, 3, 2, 1, 0, -1, -2, -3, -4 respectively
 *  : the value of the halflife in the specified unit
 *  : the value of the halflife in seconds

The alternative form has some advantages and disadvantages:
 * Advantage: It does not require maintaining two different values,   and  
 * Disadvantage: It will break if the units are used inconsistently, e.g., 1 y will sort as greater than 400 d

Also, note that  could be used instead of.

It doesn't really matter to me which way it is done -- my preferences would would be relevant if I were doing the heavy lifting. But I did want to explain the alternatives sufficiently so that if the heavy-lifter can consider an alternative. YBG (talk) 02:11, 1 April 2015 (UTC)
 * Ah yes, that makes sense to consider the magnitude first. What I'm contemplating is to have  be automatically calculated from   rather than be a separate manually-maintained value entered in the table. So there would be (from the wiki page as editors handle it) nothing more than now, except the name of the template that does the sortability magic as a wrapper around the value+unit data. DMacks (talk) 14:49, 1 April 2015 (UTC)
 * Dropping a suggestion (or distraction ;-) ). To get sortnumber added from regular value input. See /doc Convert#Time units: Module:convert can read all  inputs into seconds, and return the plain number-in-seconds only. That plain number to be fed to (=nested in)  to produce sortable code. All from a single article-editor number-space-unit input (restrictions might apply). Issue: number-unit separator is space in regular input, but Convert requires a pipe. Too fast or clear enough? -DePiep (talk) 15:39, 1 April 2015 (UTC)
 * convert tends to output scientific notation, which breaks numerical sorting because the exponent is not seen. But it does have a separate flag for emitting what we need (the raw value, no exponent problem) already specifically tagged as the hidden table-sort token. Which I only found yesterday after spending an hour re-implementing it via val. One problem is that neither "y" nor "a" are recognized as a unit of "years". Can we live with "yr", or is that too far from SI for scientific data table? It would be easy to have a special template for the isotope tables that takes "y"/"a" and convert it to "yr" (and does whatever other parsing is needed for this specific setup) for passing to underlying format/conversion templates. DMacks (talk) 16:22, 1 April 2015 (UTC)
 * About y/a/yr: best ask at template talk:Convert, Johnuniq (module editor) knows why it can/cannot be added as a unit.
 * About sortable: correct, table sortkey adding is available. To solve: requires table so we can't use disp again to prevent the second (2nd, converted, pun) column showing. Needs another look, not yet discarded. -DePiep (talk) 18:02, 1 April 2015 (UTC)

The function of  seems only to be placing the units in a separate column from the value (  alone is what appears to control output of the sortkey). We don't need that multicolumn feature here, so we can use that parameter to control the output components, such as  with the output units be the same as the input. Not sure Module:convert knows this should short-circuit the actual conversion math. Wiki editors' cost is only having to write the unit twice). DMacks (talk) 18:35, 1 April 2015 (UTC)
 * From here, I would need to go playing with it but I lack the time. About the cost: ahum, the article editor would like to input, right? That's the goal. As said, I have no time to try development in this. I'm gone, you can ping me. -DePiep (talk) 18:42, 1 April 2015 (UTC)
 * Right. I was thinking for cost if we relied solely on convert and/or val rather than a customized wrapper for them. We need the sortability feature of convert and the formatting of val. Customize wrapper seems like the way to go (at least for an initial test) until/unless the underlying ones become more unified or featureful. Another complication: appears to generate the sort-key based on the original value not the converted result--is that a bug?--so we would need to convert to a unified unit first with that template and then feed that result back to another invocation whose actual output (values/units) are completely hidden to get the unified sort-key. DMacks (talk) 16:31, 2 April 2015 (UTC)
 * I see. The module:Convert is very good in: accepting number formats, recognise units, combined units, prefixes (both symbol and name), calculate that smart sortnumber. It is not good in: return isolated results (eg, that sortnumber only), add table formatting. (btw, the input number usually returned as-is, unchanged). In my description convert-calls are hidden from the article editor. It is only used to get the plain time-quantity-in-seconds number (from any time-unit-input), the core & good {convert} trick. That seconds-number is fed into a sortkey-creator (like {nts}). The value+unit shown can be exactly the editor's input. Could work, is not very elegant. What Jimp writes, below, is about the sortvalue calculated by convert, my setup does not use that. -DePiep (talk) 07:36, 3 April 2015 (UTC)

Exploring the {Convert} option
For what it's worth, now that Jimp has given a more elegant option by below. I have created Interval ts, with Interval ts/testcases. Don't think this needs much further attention. I'll leave it there for a while. -DePiep (talk) 09:29, 3 April 2015 (UTC)
 * I had actually thought of something along those lines but we're going to run into problems with this since  gives scientific notation outside the 100 μs – 1 Gs range.
 * → 32 yr
 * → 99 us
 * Feed that into and we don't end up with something too pretty.
 * Jimp 10:42, 3 April 2015 (UTC)
 * {Val} already won. It was an issue that was to be researched, but let's save time: todo never mind. -DePiep (talk) 14:20, 3 April 2015 (UTC)
 * Jimp 10:42, 3 April 2015 (UTC)
 * {Val} already won. It was an issue that was to be researched, but let's save time: todo never mind. -DePiep (talk) 14:20, 3 April 2015 (UTC)

Exploring the {Val} option
"Another complication: appears to generate the sort-key based on the original value not the converted result--is that a bug?" Yeah, it's sort of a bug. The work-around is out but I see this as being far inferior to a notion put forth a few weeks ago at 's talk page, i.e. basing sort keys on SI base units. This seems to me to be the best option and is the option now taken by. Half-lives, for example, are converted to seconds and the number of seconds is used to create a hidden sort key using. The unit part of the sort key is currently based on the old subtemplates (so it won't cover anything added to the module since the template went Lua); however, units not covered by the old  can be added to val/sortkey. I hope this is useful. Jimp 07:11, 3 April 2015 (UTC)
 * So, for this limited goal (dimension is time only, and we may require SI units for input, reduced number input formats), we could calculate the quantity into seconds using {convert} module, and enter that number into ntsh to return the sortkey. The visible text returned can be the input I guess. Would not need {val} this way (unless the input number format is not recognised by {convert}. Is {Val} better for this, covering more scientific forms?). -DePiep (talk) 07:53, 3 April 2015 (UTC)
 * I'd say is the template for this as we're not displaying any conversion.  's purpose is to display a number or value without conversion but with all the sciency bells and whistles (scientific notation, uncertainties, etc.) that you might want.  All that was needed was a sort key for .  That's been added (and not just for time).  So, just chuck your number or value into  and the template has it sorted. Jimp 08:54, 3 April 2015 (UTC)


 * ({Val}-demo by Jimp:)

{|
 * gives


 * }
 * aha. I hadn't noticed that the sortkey was added to {Val}. -DePiep (talk) 09:22, 3 April 2015 (UTC)
 * It's my fault for rambling on too much. Jimp 09:38, 3 April 2015 (UTC)
 * No, it's great! (didn't see it was added always, in its initial setup today. It was not even documented ;-). etc.). I have nothing important to add. (minor: as you wrote, we'd like to ditch old {convert/...} some day). -DePiep (talk) 09:53, 3 April 2015 (UTC)
 * We would but I suppose it can come in handy occasionally. Jimp 10:22, 3 April 2015 (UTC)
 * Looks great. Any way to use a or a? ( a or a ) or something similar? YBG (talk) 18:11, 3 April 2015 (UTC)
 * To link a unit: use ul. See $12.3 d$ in the demo table above. Don't know about abbr. -DePiep (talk) 18:57, 3 April 2015 (UTC)
 * Let's not forget: this table was the original target ;-) -DePiep (talk) 19:08, 3 April 2015 (UTC)
 * Unfortunately, $67.93 ns$ renders as $37.12 s$ with a hyperlink to Hectare, which isn't exactly what we had in mind. YBG (talk) 21:43, 3 April 2015 (UTC)
 * Turns out $2.53 a$ ($23.54 us$) and $7.34 wk$ ($83 Ma$) produce working wikilinks, but then if you use 'y' or'yr', the wikilink may not actually be necessary. Probably should double-check the sorting also. YBG (talk) 21:52, 3 April 2015 (UTC)
 * I say: {Val} should use 1. MOS, 2. SI, 3. {Convert}. -DePiep (talk) 21:49, 11 April 2015 (UTC)

Natural occurrence of transplutonium elements
Have any of americium, curium, berkelium, or californium ever actually been detected in nature? I can't find any source besides Emsley that claims they do exist naturally, and as far as I can see, he claims that they are formed naturally in minute quantities by neutron capture in concentrated uranium ores but does not cite any source claiming to have detected them. I certainly find it plausible that he's correct, but if there haven't actually been any detections of natural transplutonium elements, should we be making that claim? - Bootstoots (talk) 18:24, 6 May 2015 (UTC)
 * (Replying here, instead of the individual articles...)
 * I added this in the first place, when the book was new, and I therefore trusted that he had actual studies backing this up (annoyingly he does not provide a detailed list of sources). Since then, though, I haven't found a source for anything beyond Pu being natural.
 * Also, it's not very plausible in the first place. Since the 239Pu:U ratio in nature is on the order of 1:1011, we can roughly assume that each atom in a uranium deposit today has about a 10−11 chance of capturing a neutron. This factor multiplies up very quickly, so that by the time we get to Bk and Cf we have not even one atom left (and this doesn't even factor in decay). The resulting values for Am (≈10−33 mg/kg) and Cm (≈10−32 mg/kg) are at least physically possible, but when we consider that it results in picogram quantities of these elements, the possibility of detection falls straight into the abyss.
 * TL;DR: we should get rid of all of these statements about natural transplutonium elements ASAP. Double sharp (talk) 08:34, 7 May 2015 (UTC)
 * I think your numbers are off: If it takes 3 neutron captures to produce Am and 4 to produce Cm, you'll get 10−27 mg/kg for Am and 10−38 mg/kg for Cm. But your point stands that detection would be practically impossible with these proportions. Still, I'd hesitate to discard Emsley's claims based on these calculations unless the claims are also disputed in more recent sources of comparable (or higher) reliability as Emsley's book; it's hard to believe Emsley just made them up. It's conceivable that neutron capture is more likely than 1:1011, or that the transplutonium elements are naturally produced by other (posibly more likely) mechanisms than multiple neutron capture, e.g. by capturing alpha particles from the uranium decay. --Roentgenium111 (talk) 11:17, 7 May 2015 (UTC)
 * Oops. (To make matters worse, these slightly OR-ish figures are in List of elements – although for Cm I was looking at the double beta decay from 244Pu, which actually seems to be more likely than the quadruple neutron capture: I don't trust my figure for that anymore, so you'll have to check it out.) The point stands, though. (And I'll fix my figures!)
 * I haven't seen anyone else even mention these claims at all, although as with Tc, Pm, Np, and Pu, it may take some time for them to become widely accepted. (And if the natural 244Pu detection is itself controversial, one wonders how much credence one should give to a single experiment finding transplutoniums.)
 * It is hard to believe though that Emsley would make things up. He explicitly mentions neutron capture as the mechanism for producing these transplutoniums, although as you note alpha particle capture would be more efficient and perhaps more likely.
 * Also, why does Emsley list 253Cf as natural but not its daughter 253Es? If there has been an experiment showing the existence of natural 253Cf that didn't have the sensitivity to detect 253Es (which is the most obvious explanation), one would think that it would be findable. But I have not yet found such an article, years after it should have appeared if Emsley could draw on it for his 2011 book. Double sharp (talk) 13:00, 7 May 2015 (UTC)
 * Has anyone considered contacting Emsley? He may provide us with some data he has and we don't. His Twitter account is easy to find (and it's active), and his email is also findable (although I cannot tell if he checks it nowadays). I may do it myself when I am in front of a laptop and have enough time to do that.--R8R (talk) 13:06, 7 May 2015 (UTC)
 * Yes, the einsteinium omission is strange and puts another shadow of a doubt on Emsley. But you wrote in Talk:List_of_elements last year that you had found corroborating sources for Am and Cm at least? --Roentgenium111 (talk) 13:22, 7 May 2015 (UTC)
 * Yes, but they were really lousy ones, posted earlier on this talk page a while ago (and the links don't work anymore, although I recall them working and stating Am as natural): the discussion is copied at Talk:Americium. I'd much prefer a published paper, which is where this sort of info would most likely be first disseminated. As for Cm, it's a very reasonable inference from two published facts: (1) 244Pu is natural and (2) 244Pu can undergo double beta decay to 244Cm. Double sharp (talk) 14:41, 7 May 2015 (UTC)
 * Thanks, I forgot the old discussion. Your Cm inference seems reasonable, but note that the natural existence of Pu-244 has apparently been put into doubt by a newer search (J. Lachner et al. Attempt to detect primordial 244Pu on Earth. Phys. Rev. C 85 (2012) 015801. ), and that Pu-244 is not in our list of known double-beta-decay isotopes. --Roentgenium111 (talk) 12:46, 12 May 2015 (UTC)
 * Hmm, that's interesting about 244Pu. We'll probably have to mark it as disputed somehow, then (although it would still be "from decay" even then, as I think natural 239Pu is pretty uncontroversial).
 * 244Pu does appear to be not in our list of known double-beta-decay isotopes, but a very rare double beta decay mode (7.3×10−9%) is listed at Isotopes of plutonium and cited to (which unfortunately requires registration, so I can't check it). I also found this source describing a 1992 experiment that found the double beta decay of 244Pu to 244Cm (with partial half-life ≥1.1×1018 years), so I think that's solid. I've added 244Pu to the table in double beta decay on that basis. Double sharp (talk) 13:20, 12 May 2015 (UTC)
 * As I understand it, Moody et al. did not observe Cm production: "We saw no evidence of Cm activity in any of the three samples." Thus they could only give a lower limit on the half-life. --Roentgenium111 (talk) 15:21, 12 May 2015 (UTC)
 * Oh, you've read the article? That's really strange, since the abstract posted says "We have searched for the ingrowth of 244Cm in a 1.45-g sample of 244Pu. We isolated a curium fraction after an ingrowth period of 1.03 yr; during this time the 244Pu sample produced ≤0.24 alpha disintegrations per day of 244Cm (95% C.L.), corresponding to a half-life for the double beta decay of 244Pu of ≥1.1×1018 yr", which seems to imply that they did see the double beta decay (as 244Cm is stated to have been isolated). I can't imagine they would make such a claim in the abstract if they didn't actually see it. Unfortunately I can't access the fulltext, which would definitely be illuminating. Double sharp (talk) 14:44, 13 May 2015 (UTC)
 * I can access it from my university account, but I haven't read it completely. Apparently the Cm detected was from contamination by a commercial Pm tracer, but the abstract (and the article) is indeed worded ambiguously. Logically, a zero result is also "≤0.24 alpha disintegrations"... --Roentgenium111 (talk) 15:17, 13 May 2015 (UTC)
 * A veritable masterpiece of ambiguous writing! I've taken 244Pu back out of double beta decay, then. Although what to make of the cite at isotopes of plutonium, then? From memory (before it needed registration) it was pretty much your average online chart of nuclides, listing decay modes among other things: so the question is where they got 244Pu double beta decay (and the figure) from. Given this situation, we should probably not even mark Cm as "from decay", then. Double sharp (talk) 15:48, 13 May 2015 (UTC)
 * I wrote an e-mail to John Emsley to ask him where he got the info on the natural occurring transplutonium elements. John was very kind and helpful when I contacted him last time on issues with the discovery of helium. --Stone (talk) 20:31, 7 May 2015 (UTC)
 * Eagerly awaiting his response! Natural transplutonium elements are very cool. Double sharp (talk) 15:02, 8 May 2015 (UTC)
 * John says that most of the info on the radioactive elements originated from mail exchanged with Walter Saxon a consultant for Oxford University Press in New York. Would be nice to know a little more about him. --Stone (talk) 20:02, 12 May 2015 (UTC)
 * He's indeed rather hard to find on Google. I'm still inclined to remove mention of natural Am, Cm, Bk, and Cf from the main periodic table, because the only source seems to be Emsley who got his info from Walter Saxon, and there's no other corroborating paper. We could still leave it as something like "Naturally occurring Am, Cm, Bk, and Cf has been reported, but not confirmed", I guess. (And to everyone who was wondering about that: yes, that makes astatine regain its position as the rarest natural element!) Double sharp (talk) 15:52, 13 May 2015 (UTC)

Semi-protected edit request on 19 May 2015
In the section 3.1 "Electron configuration", there is a line saying:

"The electron configuration for neon, for example, is 1s2 2s2 2p6. With an atomic number of ten, neon has two electrons in the first shell, and eight electrons in the second shell"

Which is incorrect, as in about the middle of said line, it says "eight electrons in the second shell", whereas neon actually has six electrons in the second shell, which is also stated in the next sentence "two in the s subshell and six in the p subshell".

Please change this to be correct, as it confused me a little bit, and it may confuse others in the future.

NewGarbo (talk) 05:33, 19 May 2015 (UTC)
 * Second shell contains s and p subshells together. Look at numbers before the letters in configurations, they represent shells. 2 in this case represents that they're in second shell. So the article info is correct and no changes were needed. Planet  Star  05:52, 19 May 2015 (UTC)

Edit request 20 June 2015
I would like to add following link to "See also" section: ❌ that is a promotional site, promoting its advertisers. - Arjayay (talk) 21:11, 20 June 2015 (UTC)
 * Interactive periodic table

"Periodic" table
"Although precursors exist, Dmitri Mendeleev is generally credited with the publication, in 1869, of the first widely recognized periodic table." I'm not an expert but I guess this is wrong. The periodic table is based on the periodic law which Mendeleev discovered, right? So all other tables before were systematic tables but not periodic tables. — Preceding unsigned comment added by Wolk777 (talk • contribs) 13:48, 12 June 2015 (UTC)
 * Did not, for example, John Newlands produce a precursor with periodicity indeed? -DePiep (talk) 15:28, 18 June 2015 (UTC)

Hmm, ok. I meant it was "part periodic", not the same as the modern periodic table. — Preceding unsigned comment added by Wolk777 (talk • contribs) 17:23, 20 June 2015 (UTC)
 * Would "Although less coherent precursors exist" do? Sandbh (talk) 23:56, 20 June 2015 (UTC)

Periodic Table (of Elements?)
I was a bit bothered and confused by the title of the page. A periodic table is merely a type of table design, so this one should be, and generally is, called the Periodic Table of Elements. Not wanting to appear ignorant, I came here first, since surely I can't be the first of this opinion, and the matter must have been settled before. What is the reason for the shortened, generalized title? Surely "Periodic Table" could just redirect to "Periodic Table of Elements", and the disambiguation is plainly clear.

In addition to this, perhaps a page should be created for the sort of table itself, with a link to the Table of Elements. — Preceding unsigned comment added by Zekava (talk • contribs) 23:25, 6 July 2015 (UTC)


 * From my experience, "periodic table" is the most common name for the table (when it comes to English. Say, in German, they usually speak about the "periodic system of elements"), hence the title for the article. Plus, it's just simpler, and when people talk about a periodic table, they usually mean the one that orders chemical elements ("It is the greatest happiness of the greatest number that is the measure of right and wrong."). Also, note the line just before the lead section starts:


 * This article is about the table used in chemistry. For other uses, see Periodic table (disambiguation).


 * It helps us cover the other cases.--R8R (talk) 00:45, 7 July 2015 (UTC)
 * "A periodic table is merely a type of table design" - I don't think so. One can not design a table (cols &times; rows, headers) to be periodic when empty. (The periodicity here only shows when the element's atomic numbers are added - not without them. I.e. when filled, not when designed). Also, "Periodic table" is a long time established common name. So by WP:PRIMARYTOPIC (re WP:disambiguation) this title is considered not ambiguous. Even when IUPAC would use the longer name (I don't bother to check), we can use this short one for being the WP:commonname. Checking the DAB Periodic table (disambiguation) page, I see that there is only one other PT, and that one takes its title by inspiration of this one (as many other, less encyclopedic PT's have). Periodic table of elements correctly redirect to this page. One question: how is it "bothering and confusing" that you arrive on this page while you were looking for it? -DePiep (talk) 07:55, 7 July 2015 (UTC)
 * I did not mean that I was "bothered and confused" by any difficulty reaching this page. I merely meant that I was bothered by the shortness and apparent informality. I can understand all of the reasons for the title now, thank you. — Preceding unsigned comment added by Zekava (talk • contribs) 18:53, 7 July 2015 (UTC)
 * Yes, informality is quite allowed in article titles. Or a 'common title', as we say. For example the page is titled simply Bill Clinton. It's OK itf it does not cause misunderstandings. -DePiep (talk) 23:15, 7 July 2015 (UTC)