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WikiProject Chemistry (Rated Project-class)
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Good article reassessment for Persistent carbene[edit]

Persistent carbene has been nominated for a good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article.

The references for this article appear to be entirely unrelated to the content. Maybe I'm completely misunderstanding something, so could someone else take a look and see if they agree or not? All the references were added in a single edit 15 years after the text was written, which seems odd to me too. Marbletan (talk) 19:54, 7 March 2023 (UTC)Reply[reply]

Agree, none of the references are related to this topic. We could ask user:RowanJ LP who added these cites to check them out. Others that Rowan added to other articles, including chemistry topics, the same day appear OK. Graeme Bartlett (talk) 22:44, 7 March 2023 (UTC)Reply[reply]
The page is virtually an orphan and the term "Polypropylene polybenzyl isocyanate" returns only 9 hits in Google Scholar. The page states that it is a polyurea, but that is at odds with the given chemical name. The similarly named "Polymethylene polyphenyl isocyanate" (essentially an oligomeric form of MDI) returns many more hits. Both compound are abbreviated PPI, which might lead to confusion. Project Osprey (talk) 09:40, 8 March 2023 (UTC)Reply[reply]
It was the name "Polypropylene polybenzyl isocyanate" that brought my attention to the article in the first place. I couldn't parse that as a meaningful chemical name. After reading the article, I still can't. I searched SciFinder and got no scientific journal hits on that name. It's possible that the few Google hits on this term have merely originated from this Wikipedia article. It seems to me that, at the very least, the subject of this article fails to meet Wikipedia's notability guidelines and 100% of the content of the article cannot be verified. For now, I've added {{disputed}} and {{notability}} templates to the article. Should it be deleted? Marbletan (talk) 14:26, 8 March 2023 (UTC)Reply[reply]
Yes, I think a PROD is warranted in this case. --Project Osprey (talk) 15:25, 8 March 2023 (UTC)Reply[reply]
That article was created by User:WhatamIdoing who is still very prolific (and competent). They might like to comment, although IMO the end result will be a deletion. Mike Turnbull (talk) 16:55, 8 March 2023 (UTC)Reply[reply]
I have no memory of creating this, and no particular attachment to it. Yilloslime made a correction early on, is also still active, and probably knows more about chemicals than I do.
I think the biggest challenge in re-constructing this was that another editor blanked the original sources. You can see one of them at (the others don't seem to have been archived), but this source gives the chemical name "polymethylene polyphenyl isocyanate". Could those be the same thing, just one using a different/outdated naming convention? (I would have copied and pasted the chemical name from a source [to avoid typos], so it must have been in at least one of the cited sources at the time.) WhatamIdoing (talk) 05:41, 9 March 2023 (UTC)Reply[reply]
Based on this comment and on Project Osprey's first comment above, I'm now confident that the article content is specific to polymethylene polyphenyl isocyanate and that one of the original sources referred to it as polypropylene polybenzyl isocyanate, either as a typo or misnomer, and that name got carried into the title of the Wikipedia article. Unless there is any objection, I will rename the article polymethylene polyphenyl isocyanate, remove the current useless references, restore WhatamIdoing's original sources, and try to find additional content/sources to improve the article. Marbletan (talk) 15:17, 9 March 2023 (UTC)Reply[reply]

Joseph DeRisi Career draft request[edit]

Hey there! I'm trying to improve the biochemist Joseph DeRisi's Wikipedia page, and thought the WP Chemistry Talk page might be a good place to find interested editors. A colleague of mine has composed a new Career draft for the DeRisi page that revises parts of the current Career section for readability, adds new information about Dr. DeRisi's professional life, and removes a few less-than-encyclopedic details. There's currently an open edit request on the DeRisi Talk page asking editors to review that section draft. I'll put a link to the full draft here, as well.

In the interest of transparency: I'm a COI editor working on behalf of Chan Zuckerberg Biohub. Dr. DeRisi is president of CZ Biohub SF. My full COI disclosure is on my user page. If anyone wants to review this Career draft, I'd be immensely grateful for the help. Thank you! K at CZ Biohub (talk) 19:55, 15 March 2023 (UTC)Reply[reply]

Antioxidant could use extra eyes[edit]

Antioxidant gets about 740 views per day, which is high for us. In this article, the public directly interacts with a lot of chemistry. The article is ok (former FA), but it would benefit from additional curation. The topic susceptible to fringe science. Another problem is that many compounds have some sort of antioxidant activity, of course. Lastly and one of my pet peeves, the article is loaded with primary refs vs refs to books and reviews. If you see issues, please leave a note here or on Talk:Antioxidant. --Smokefoot (talk) 17:03, 17 March 2023 (UTC)Reply[reply]

I should help here, as this is an area I'm close to professionally, but I've been pushed for time recently. This recent review may prove helpful. doi:10.1039/D1CS00265A Project Osprey (talk) 17:11, 17 March 2023 (UTC)Reply[reply]

Nonmetal: Help with copyediting?[edit]

Is there anyone here that could help? The nonmetal article has been to PR twice and partly copy edited by User:Jo-Jo Eumerus and User: John. I listed it at the WikiProject Guild of Copy Editors request page on February 2nd 2023 with so far no takers. After the copy-edit I intend to list it for a sixth FAC nomination. Thank you, Sandbh (talk) 03:50, 9 April 2023 (UTC)Reply[reply]

I'd like to note some non-copyedit issues; in the "Definition and applicable elements" section for example, why is Steudel 2020 so important as to be mentioned by name? Jo-Jo Eumerus (talk) 10:23, 9 April 2023 (UTC)Reply[reply]

Only a half-dozen monographs on nonmetals have been published over the last half-century. Steudel 2020 is the 2nd edition of a work first published in 1977. My general presumption is that after 43 years between editions Steudel 2020 is probably a good starting point. Sandbh (talk) 12:39, 9 April 2023 (UTC)Reply[reply]

Steudel's book is on Main Group Chemistry, which seems in academic circles to be a more common subdivision of inorganic chemistry. Also if one looks at awards, those also are for Main Group, not Nonmetal Chemistry. There is also a journal on Main Group Chem. Nonmetal is sort of an older classification based on conductivity of the elements. So one approach would be to shift most content to Main Group Chemistry, and leave a short article on Nonmetals. IMHO--Smokefoot (talk) 13:32, 9 April 2023 (UTC)Reply[reply]

Steudel's book is called, Chemistry of the Non-metals: Syntheses - Structures - Bonding - Applications. Nothing specific about main group elements. The first paragraph of the preface is:

"How would our planet Earth look like without nonmetals? No water, no air, no life! Not even rocks and sand since oxygen and silicon are responsible for 72.7% of the mass of crustal rocks on the Earth. The human body consists of 96.6% of oxygen, carbon, hydrogen and nitrogen. If all the other nonmetallic elements are added, we end up with 98.0%. Nonmetal compounds play a crucial role in our daily life and in industry as you will see in this book. It is therefore obvious that the chemistry of the nonmetals is a major part of the chemical education at all levels, from high school to university."

Conductivity of the elements has never worked well given carbon is a metallic conductor in the direction of its planes (better than some metals) and arsenic and antimony are metallic conductors.

The earliest attempt I found for distinguishing between metals and nonmetals dates from 1811 and was based on fusibility, malleability, and ductility. Further attempts were based on opacity 1821; cation formation 1911; the Goldhammer-Herzfeld criterion for metallization 1927; bulk coordination number 1949; acid-base character of oxides 1956; minimum excitation potential 1956; sonorousness 1962; physical state 1966; sulfate formation 1966; critical temperature 1973; oxide solubility in acid 1977; enthalpy of vaporization 1986; liquid range 1991; temperature coefficient of resistivity 1999. The latter is unsatisfactory as it results in plutonium being counted as a nonmetal (which it most certainly is not) since it increases its electrical conductivity when heated in the temperature range of around –175 to +125 °C.

The distinction between metals and nonmetals is a classic feature of many periodic tables (the periodic table being an icon of chemistry, and science) by way of the zig-zag line attempting to delineate between the two great classes. Sandbh (talk) 05:51, 10 April 2023 (UTC)Reply[reply]

The zig-zag line "between" elements more commonly appears as a separate, third major class: metalloids. In the reply here, and in the nonmetal article, by the same editor, this classification feature is ignored (not addressed). Also wrt classification, the article heavily poses new, uncommon and ad-hoc subclassification ("being intermediate between metals and nonmetals", "nonmetal halogens"). So apart from copy edit needs, the issue of undue weight & doubtful classification is entrenched. DePiep (talk) 11:46, 10 April 2023 (UTC)Reply[reply]
OK, youre right about Steudels book title. But I am correct about Main Group Chem in awards and journals. The recent ACS National meeting in Indy "Search Results: 3941 results for 'main group'." "Search Results: 6 results for 'nonmetal'." So the vote is pretty clear at least on this side of the pond. Nonmetal a fuddy duddy term used by nonchemists (and in the case of Ralf Steudel, deceased chemists).--Smokefoot (talk) 13:15, 10 April 2023 (UTC)Reply[reply]

DePiep: Examining the periodic tables shown in 67 chemistry books immediately at hand to me gave the following result:

Periodic table type Number Percentage
No dividing line 29 43%
Dividing line only 19 28%
Dividing line & metalloids shown 12 18%
Metalloids shown, no dividing line 7 10%

So, roughly 70% of the time there is no dividing line or a dividing line only.

In the other 30% of cases the metalloids are shown.

Rather than being "more commonly" shown, the metalloids are sometimes shown either in conjunction with the dividing line or by themselves.

Re the article ignoring metalloids, it says, in part:

"On a standard periodic table, they [the metalloids] occupy a diagonal area in the p-block extending from boron at the upper left to tellurium at lower right, along the dividing line between metals and nonmetals shown on some tables."

The term "metalloid" appears 49 times.

The phrase, "intermediate class between the metals and the nonmetals" needs to be appreciated in terms of its context within the article, thus:

"The elements commonly recognized as metalloids namely boron; silicon and germanium; arsenic and antimony; and tellurium are sometimes counted as an intermediate class between the metals and the nonmetals when the criteria used to distinguish between metals and nonmetals are inconclusive."

For the term "nonmetal halogens" here are some examples from the literature:

  •  "In a similar manner the nonmetal halogen elements are arranged."
Essentials of Chemistry - Page 54, Luros G · 1955
  •  "The alkali metals of Group la combine readily with the nonmetal halogens of Group VIIa."
General Chemistry - Page 87, John Arrend Timm · 1966
  •  "The nonmetallic halogen atoms easily pick up an electron, thus forming halide ions."
Chemistry Decoded - Page 346, Leonard W. Fine · 1976
  •  "Iodine is a nonmetallic halogen , having the lowest reactivity of any substance in this group."
Properties of Nonmetallic Fluid Elements - Volume 3, Part 2 - Page 115, Yeram Sarkis Touloukian, ‎Cho Yen Ho · 1981 · ‎p. 115
  •  "An activity series for the nonmetallic halogens was given in Chapter 6."
Understanding Chemistry - Page 386, Robert J. Ouellette · 1987
  •  "Other properties are similar to those of the nonmetallic halogen elements in Group VIIA or 17 in the second column from the far right of the table…in this case, the nonmetal halogen element is reduced to its halide ion."
Chemistry: A Basic Introduction - Pages 125, 271, George Tyler Miller · 1987
  •  "Iodine resembles bromine because they are nonmetallic halogens that form compounds like those of chlorine."
Chemistry - Page 8, Harold D. Nathan · 1993, p. 8
  •  "What causes gold to emulate many properties of the nonmetallic halogens?"
Chemical Principles, Page 549, Steven S. Zumdahl · 1995
  •  "Particular but we must not forget the novel involvement of the non-metal halogens."
The Chemistry of Evolution: The Development of our Ecosystem, R.J.P Williams, ‎J.J.R Fraústo da Silva · 2005
  •  "Among the other nonmetal halogens used to partially halogenate metal oxides…"
Inorganic Reactions and Methods, The Formation of Bonds to…, A. P. Hagen · 2009, p. 221
  •  "Non-metallic halogens such as chlorine, iodine and bromine are salt-forming elements."
— "TRPM7 is regulated by halides through its kinase domain", H Yu, Z Zhang, A Lis, R Penner, A Fleig - Cellular and molecular life… 2013
  •  "Nonmetallic halogen element of atomic number 53…"
Hawley's Condensed Chemical Dictionary - Page 765, Michael D Larrañaga, ‎Richard J. Lewis, Sr., ‎Robert A. Lewis · 2016
  •  "Non-metallic halogens are very attractive."
— "Hydrothermal preparation of visible-light-driven Br-doped Bi2WO6 photocatalyst", P Dumrongrojthanath, A Phuruangrat, S Thongtem… Materials Letters, 2017 - Elsevier
  •  "…chlorine; element #17; a nonmetal halogen gas."
Trauma, 8th Edition - Page 1139, Moore et al. 2017, p. 1139
  •  "…and a more detailed grouping in families of: alkali Earth, alkaline Earth, transition metal, rare Earth, other metal, metalloid, and nonmetal halogen to noble gas."
Illustrated Encyclopedia of Applied and Engineering Physics, Robert Splinter · 2017, p. 382

--- Sandbh (talk) 06:19, 12 April 2023 (UTC)Reply[reply]

Sandbh: Yes the Nonmetal term arises when the Periodic Table is discussed. We need an article on Nonmetal for sure. It would contain a chart of electrical conductivity of some elements and discuss allotropy. But the chemistry of the MG elements would be developed in the now short article on MG chem. Again, thanks for the extensive response. You are correct that nonmetal is common, if somewhat archaic (fuddy-duddy) but the MG term rules presently and pretty completely in the academic world.--Smokefoot (talk) 13:28, 12 April 2023 (UTC)Reply[reply]
I note it to inform or warn interested copyeditors that, apart from copyediting, the article might need structural changes. I don't think this discussion belongs here. DePiep (talk) 06:33, 12 April 2023 (UTC)Reply[reply]

“ …we focus mainly on the gross structure – the metals are here, the non-metals are there, and so on. Once they have grasped this, you can start to show that there’s some order to it. We talk about the Group 1 alkali metals and start to see that they’re all similar in some way. Then at the other extreme there are the…halogens. The idea that the table shows us how to group similar elements starts to come together in this way. ”
Niki Kaiser (2019)

Notre Dame High School,
Norwich, UK

Source:Unwrapping the periodic table

Smokefoot: The distinction between metals and nonmetals is a part of Chemistry 101. For example, the Royal Society of Chemistry's English Chemistry Curriculum Map for KS4 (Years 10 and 11) says, "Trends in the periodic table; Explain the reactivity and general properties as related to the atomic structure of groups 1, 7 and 0; between metals and non-metals."

When I search American Chemical Society journals for “metals” I get 287,959 hits; for “non-metals” I get 286,100 hits.

--- Sandbh (talk) 06:19, 12 April 2023 (UTC)Reply[reply]

Again I assert that a small collection of editors have created a sort of walled garden called Nonmetal, with lots of pictures of minerals (that are off topic). Universities offer courses on Main Group Chem, not on Nonmetal chem. ACS gives an award for MG Chem, a journal is entitled MG Chem. RSC also has a MG chem section. Greenwood and Earshaw (the bible of this area): Main Group:52 entries, nonmetal(s/ic): 6 entries. My guess is that the supporters of this article's title do not interact with contemporary inorganic chemistry. In other words, the title has been hijacked by some hobbyists, not professionals. In the end, it doesnt matter I guess. Thanks for taking the time to respond.--Smokefoot (talk) 13:10, 12 April 2023 (UTC)Reply[reply]

Smokefoot: Thanks for the entertaining assertions. Responding to your earlier post, electrical conductivity figures are given in the Comparison section. Allotropy is discussed in the Allotropes section. "Main group chemistry" returns 343,000 hits on ACS Journals cf. ~287,000 each for "metals" and "nonmetals". That MGC is ~20% more popular than either "metal" or "nonmetal" does not strike me as being particularly significant.

The assertion that there are "lots of pictures of minerals (that are off topic)" does not withstand scrutiny. The article has 12 pictures of nonmetals; in addition there is a picture of a cluster of purple fluorite CaF
, a fluorine mineral; and another picture of arsenic sulfide mineral As4S4. The image of fluorite is there as the most common fluoride mineral and main source of fluorine for commercial uses. Arsenic sulfide is composed of two elements each with a predominately nonmetallic chemistry.

According to the electronic version of Greenwood & Earnshaw 2ed, "main group" is mentioned 58 times and "nonmetal(s/ic)" 62 times.

A Google Ngram search for "main group chemistry" and "nonmetals" shows that "nonmetals" appears 90 times more frequently than "main group chemistry" in the English corpus.

Between (i) ACS Journals; (ii) the Royal Society of Chemistry's education curriculum; (iii) G&E; and (iv) Ngram, nonmetals are alive and well and far from having fuddy-duddy status.

In passing, I note that 2019 calculations suggest that copernicium (in the d-block) has a large band gap of 6.4 ± 0.2 eV, which should be similar to that of the noble gas radon (predicted as 7.1 eV) and would make it an insulator; bulk copernicium is predicted by these calculations to be bound mostly by dispersion forces, like the noble gases. If confirmed this would represent the first example of a non-main-group nonmetal.

--- Sandbh (talk) 07:33, 14 April 2023 (UTC)Reply[reply]

Not helpful to expand & extend your OP here this way. deviation, offtopic, multiforum, possible repetition/incompleteness. btw, entertaining assertions is dismissive. DePiep (talk) 09:04, 14 April 2023 (UTC)Reply[reply]
OK, my efforts failed. I would be interested in reading your publications and hearing your lectures one of these days. --Smokefoot (talk) 14:27, 14 April 2023 (UTC)Reply[reply]

Thanks very much Smokefoot. Your input was an important contribution. To the extent that we disagreed my view is fairly well captured in this quote:

"Disagreements can be unpleasant, even offensive, but they are vital to human reason. Without them we remain in the dark."


  •  The genesis of manned flight, by the Wright Brothers, arose out of disagreement. By allowing their arguments to run hot, the Wrights were able to beat all the experts in the world.
  •  The idea that people with different views can vigorously yet co­operatively disagree is essential to democratic society.
  •  A good scrap can turn our cognitive flaws into collective virtues.

Truth wins out only after an exchange of arguments. The answers that emerge will be stronger for having been forged in the crucible of our disagreement.

That is very gracious of you to express an interest in my publications. A list of them is here. The closest I came to a lecture was the virtual presentation I gave to the ACS Spring Technical Program, in 2022. --- Sandbh (talk) 08:03, 15 April 2023 (UTC)Reply[reply]

My general impression is that the metal vs. nonmetal (possibly with or without metalloids/semimetals) distinction is generally used by:

  1. Those teaching school-level chemistry, where it becomes a proxy for electronegativity, conductivity, and many other properties. Often it is not exactly and rigorously stated what the defining properties are (nobody agrees on that anyway). This sort of works at that level when you only deal with obvious things like alkali metals and halogens, but is a bit too naïve once you go any further, because once you get outside the most extreme cases, the properties school-level chemistry tells you are stereotypically metallic don't tend to occur together. (Tungsten conducts well and is very dense but tends to form polyoxometallates in solution; meanwhile germanium has some cationic chemistry but is only a semiconductor.) Moreover, properties tend to change continuously down a group: the structures of bulk P, As, Sb, and Bi are as good an example as any, and there's no very natural place to make the cut. (One could start an unproductive myriad-word argument about that but that in itself proves the continuity. As does the fact that it is partly a matter of tradition as opposed to actual clear chemical differences: Russian-language school texts will generally call Sb a metal, while English-language ones generally will not.) In consequence you will still find it in school textbooks and the chemical education literature (e.g. Sandbh's linked paper), but modern researchers will tend to handle things group-by-group, which is more pragmatic given the continuities. Since chemical education generally matches older views of a topic (partly for good pedagogical reasons in which the way you learn something mimicks the way humanity as a whole has been learning it, and partly because no one got the memo from current research) it is natural that older books will talk more about metals vs nonmetals than newer ones do, though even those older books sometimes equivocate on which elements are which (I know one that calls antimony a metal and a nonmetal on two different pages). Sandbh's list of nonmetal monographs itself already proves that metal vs nonmetal is something that was already going out of style as the main division by the 1970s.
  2. Those doing condensed-matter physics, where it is purely a one-property thing about conductivity, and so is not really a way of classifying elements but substances (under such schemes, for example, grey arsenic is a metal while black and yellow arsenic aren't).
  3. People naming superheavies (which was only an issue for 117 and 118 in the halogen and noble gas groups), which is basically just briefly resurrecting the old classification so that the names don't look out of place, and not really using it in practice. Besides, the average inorganicker does not care about superheavies.

Personally, I'd rather leave the term to condensed-matter physicists, for whom it is actually useful. Proving my point, the IUPAC Gold Book only defines things like "metal-nonmetal transition" in the condensed-matter-physics meanings. But I guess students are likely to look it up because they see it in textbooks. I agree with Smokefoot's solution of noting that this is basically a historical and chemical-education term (those fields naturally overlap) with no clear definition and that in modern inorganic research one simply speaks of main-group elements without worrying too much where to draw the lines in a continuous landscape. I'd add that condensed-matter physicists have picked it up with a meaning useful to them, though. Double sharp (talk) 07:35, 16 April 2023 (UTC)Reply[reply]

Thanks Double sharp for your interesting thoughts.
There is no reliable evidence, that I know of, to sustain a suggestion that, "metal vs nonmetal is something that was already going out of style as the main division by the 1970s."
The ACS and RSC both have periodic tables that feature a distinction between metals and nonmetals. The ACS periodic table is further included on the back of their membership cards. The RSC table is especially interesting since it counts the metalloids as nonmetals, rightly so since metalloids have predominately nonmetallic chemistries. Less notably, the Encyclopedia Britannica periodic table maintains a metal-nonmetal dividing line.
--- Sandbh (talk) 04:38, 23 April 2023 (UTC)Reply[reply]
The list of nonmetal monographs you linked to contains only three entries after the 1970s. And one of them is simply an updated version of one of those 1970s books. I do not dispute that the metal vs. nonmetal division continues to be used. I simply note that this looks like good evidence that it's not the main division used by practicing chemists. Stuff used on decorative periodic tables is something different and is closer to my #1. Incidentally, you are not telling the full story: the RSC table counts the metalloids as both metals and nonmetals. As for "predominately nonmetallic" chemistries, note that by any reasonable definition At has more of that than Sb does (after all, astatine will form simple anions), yet relativistic calculations suggest that At is a metal in the physicist's sense and Sb is only a semimetal. Of course, in spite of this, it would be pretty eccentric to discuss astatine with anything but the halogens. Again, that shows that the mass of vaguely correlated properties that school texts will tend to identify as pinpointing nonmetallic character do not actually have that simple a relationship with each other. This perhaps sheds some light on why chemists tend to consider things group-by-group today instead of futilely debate on where to draw lines, and why physicists have specialised the metal vs. nonmetal classification to just conductivity. Double sharp (talk) 21:51, 23 April 2023 (UTC)Reply[reply]

If there is so much disagreement about the article topic, an idea I would pursue is to a) assemble all the most commonly cited textbooks or other overarching sources on chemistry and b) draft a new article text that discusses (compares) the various definitions of "nonmetal". Jo-Jo Eumerus (talk) 08:25, 23 April 2023 (UTC)Reply[reply]

By this thread, the claim is that "main group" and "metal-metalloid-nonmetal" chemistry/physics are different topics and so to be handled in two different articles. This is not about the concept of "metal" evolving (changing) into "main group". BTW, both articles exist. DePiep (talk) 10:49, 23 April 2023 (UTC)Reply[reply]
I agree. They are different classifications. One has overtaken the other in the literature, but they are not synonymous. Double sharp (talk) 21:51, 23 April 2023 (UTC)Reply[reply]

Thanks @Double sharp:

The assertion that, "one of them is simply an updated version of one of these 1970s books" is not supported by the following comments in the preface to Steudel (2020):

Nonmetal compounds play a crucial role in our daily life and in industry as you will see in this book. It is therefore obvious that the chemistry of the nonmetals is a major part of the chemical education at all levels, from high school to university.
The book you are holding in your hands is very special to me. I wrote the first German edition at the very early stage of my academic career...It originated from my lectures at the Technical University Berlin, the place known as a hotspot of nonmetal chemistry research. With the years, the book became my lifetime project. I was fortunate enough to share my passion and interest in the chemistry of the nonmetals (and the yellow element in particular) with many friends and colleagues in academia and industry all over the world. Thus, the book was always nourished with the modern developments in fundamental and industrial research.
Five editions of this monograph have been published by de Gruyter, Berlin/Boston, each time completely modernized and extended. This newest international edition is an updated translation of the latest German edition of 2013. I am grateful to my two younger colleagues who share the same passion...
Numerous review articles and original publications are cited in footnotes and encourage the readers to study certain topics more extensively. To keep the size of the footnotes with nearly 1000 references under control, however, only one author is given if there are more than three.
Literature closing date was spring 2019.
De Gruyter Publisher in Berlin supported this project from day 1, so that many people who worked with me all these years should be acknowledged.
Many colleagues, coworkers and students contributed to the success of this book with their comments and suggestions and I will be happy to hear from the readers of this edition too

My comment about the RSC's treatment of metalloids was wrong. Thanks for pointing that out.

I agree about At. While it could reasonably be presumed to be a metalloid based on ordinary periodic trends, relativistic effects—as seen in gold, mercury, and the heavier p-block elements—are expected to result in condensed astatine being a ductile metal. Astatine could also be expected to show significant nonmetallic character, as is normally the case for metals in, or in the vicinity of, the p-block.

Regarding futilely debating where to draw lines, chemistry has all sorts of fuzzy definitions and the article accommodates and acknowledges a divergence of views.

The physicists' metal vs. nonmetal classification on the basis of electrical conductivity probably works for them as a simple generalisation but does not accommodate the view that chemistry is not reducible to physics. It potentially causes some difficulties elsewhere as it results in carbon and arsenic being counted as metals.

Thanks @Jo-Jo Eumerus: There is no substantive disagreement about nonmetals in chemistry beyond the par-for-the-course fuziness at the edges. The article surveys the varying suggested definitions of a nonmetal in the suggested distinguishing criteria section. --- Sandbh (talk) 04:45, 24 April 2023 (UTC)Reply[reply]

You yourself said at the beginning of this thread that Steudel 2020 is the 2nd edition of a work first published in 1977. And Steudel himself, according to your quote, admits that this is a modernized and extended version of a book he first wrote at the very early stage of [his] academic career. It amazes me that you quote all of this and then claim that my assertion that this "is simply an updated version of one of these 1970s books" is not supported. Double sharp (talk) 18:49, 24 April 2023 (UTC)Reply[reply]

Well, yes, Steudel 2020 is the 2nd (English/international) edition of a work first published in 1977. I added, My general presumption is that after 43 years between editions Steudel 2020 is probably a good starting point. Until I read your assessment of Steudel 2020 as simply an updated version of one of these 1970s books it had not occurred to me to read the preface. Upon which I learnt that Steudel 2020 is an updated translation of the 5th German edition of 2013, incorporating the literature up to Spring 2019. That seems clear enough to me. --- Sandbh (talk) 00:10, 25 April 2023 (UTC)Reply[reply]

An update of an update is still an update. Double sharp (talk) 21:22, 27 April 2023 (UTC)Reply[reply]

Project-independent quality assessments[edit]

Quality assessments are used by Wikipedia editors to rate the quality of articles in terms of completeness, organization, prose quality, sourcing, etc. Most wikiprojects follow the general guidelines at Wikipedia:Content assessment, but some have specialized assessment guidelines. A recent Village pump proposal was approved and has been implemented to add a |class= parameter to {{WikiProject banner shell}}, which can display a general quality assessment for an article, and to let project banner templates "inherit" this assessment.

No action is required if your wikiproject follows the standard assessment approach. Over time, quality assessments will be migrated up to {{WikiProject banner shell}}, and your project banner will automatically "inherit" any changes to the general assessments for the purpose of assigning categories.

However, if your project has decided to "opt out" and follow a non-standard quality assessment approach, all you have to do is modify your wikiproject banner template to pass {{WPBannerMeta}} a new |QUALITY_CRITERIA=custom parameter. If this is done, changes to the general quality assessment will be ignored, and your project-level assessment will be displayed and used to create categories, as at present. Aymatth2 (talk) 13:19, 10 April 2023 (UTC)Reply[reply]

Request for comment at alchemical symbol[edit]

Okay, I know this is a bit off-topic for this project, and not sure chemists would even care that we cover alchemy accurately, but I'd appreciate comments on the RfC on the talk page, or even for someone here to edit the contested bit (or the whole article, for that matter). We have an edit-warrior insisting that we keep a purported old alchemical symbol despite an absence of RS's. I've trimmed a lot of the cruft from that article, don't know why this bit in particular is a problem other than the two of us clashing elsewhere. (The editor says I'm being "disingenuous" by insisting that magnesium is not the same as magnesia.)

Our article has for years claimed that ⚩ is an alchemical symbol for magnesium. The source was Unicode, from versions 4.1 to 5.2. The identification with magnesium was retracted in Unicode 6. It originally came from the proposal for the symbol by Michael Everson, in L2/03-164 (p. 3), whose sole source was an offhand comment in Carl Liungman (1993) Tanketecken, later released (or revised) in English as Dictionary of Symbols, a lay treatment of symbols in general, not alchemy. The people I spoke to at Unicode couldn't find a record of why they retracted the identification, but they suspect it was due to an objection by someone at the Newton Chymistry Project, which is digitizing Isaac Newton's alchemical manuscripts.

The WP editor has now modified the identity of the symbol to "magnesia (alba), source of later magnesium", still claiming the support of Unicode, as if that were a RS. The changed identification is based on Louis Reutter de Rosemont (1931) Histoire de la pharmacie a travers les ages, where a rather similar-looking symbol (I can't judge if it's a variant of ⚩; it looks like it's got a Mercury cap in it) is identified as "magnesia". (See the chart here: Reutter de Rosemont; chemical symbols Wellcome L0014471.jpg, 8th symbol in the left-hand column.) Not as magnesia alba, which is the magnesium salt, so for all I know it might be the manganese salt or some other mineral that once went by the name of 'magnesia'.

Anyway, comments/edits/rewrites welcome. — kwami (talk) 07:55, 21 April 2023 (UTC)Reply[reply]

The removal seems correct to me, since the source's claim was later retracted. I cannot comment on the alchemy, though. Double sharp (talk) 09:16, 21 April 2023 (UTC)Reply[reply]
@Kwamikagami Metallic magnesium was not isolated until 1808 (see that article). However, magnesium oxide, also known as magnesia alba, has been known since antiquity and so, in my opinion, is much more likely to have been what the alchemical symbol meant. Mike Turnbull (talk) 12:55, 21 April 2023 (UTC)Reply[reply]
Yes, and if we had a RS that the symbol was for magnesia alba, that would be good by me. But we don't. We have what might be a variant or misprinting of the symbol (with what appears to be an 🝁 added to the right stroke) for "magnesia", which could be either a magnesium or a manganese compound (magnesia nigra: Manganese#History). And AFAICT we do know that there were were alchemical symbols for manganese. If someone can find a RS for the claim, I have no problem keeping it. — kwami (talk) 20:03, 21 April 2023 (UTC)Reply[reply]

New article needs input[edit]

Greetings. Aldol reactions was just created. Not sure how this differs from Aldol reaction. Would appreciate some input from the project on the article's talk page. Onel5969 TT me 09:37, 21 April 2023 (UTC)Reply[reply]

There is also relevant discussion at Talk:Aldol reaction, a previously featured article now rated "B". Mike Turnbull (talk) 14:47, 21 April 2023 (UTC)Reply[reply]
Thanks. Onel5969 TT me 18:23, 21 April 2023 (UTC)Reply[reply]

Isomalt: a mixture?[edit]

Hello, I would be grateful if an expert could help me out at Talk:Isomalt#It is a mixture of two disaccharides, but which ones? The article isomalt is a bit unclear about the exact composition of isomalt. Thanks, AxelBoldt (talk) 22:01, 21 April 2023 (UTC)Reply[reply]

Covalent compounds and naming[edit]

Hello. There are at least 13 articles on compounds that are not ionic (e. g. TcF
, RuF
, RhF
, WF
, ReF
, OsF
, IrF
, PtF
, RuF
, VF
and even XeF
, XeO
and XeO
) but according to the articles, they have an official name containing the oxidation number in Roman numerals.

Also, there are at least 2 articles (not redirects!) about non-ionic compounds not using the correct name as their title (e. g. Ir
and Re

Or am I using the rules of chemical nomenclature wrong? Alfa-ketosav (talk) 16:26, 25 April 2023 (UTC)Reply[reply]

There isn't such a rule. Stock nomenclature is correct even for obvious covalent compounds. We just tend to avoid it then because in those cases it is usually not the most common name. Besides, it is impossible to clearly define the boundary between covalent and ionic, since that is a continuum (and forgets about cases like IrO2 which has metallic conductivity). We already have exceptions like mercury(II) chloride (which is, despite the low oxidation state, molecular). Double sharp (talk) 21:25, 27 April 2023 (UTC)Reply[reply]

Ethidene dichloride[edit]

Afternoon folks!! I notice there isn't an article or redirect on this substance, which was used as an artificial Anaesthetic around the 1860-1890's. I wonder if its interesting enough for somebody to do an article. I don't know if there is an article already, not being a chemist. Would it be this 1,1-Dichloroethane? A google search seems to point to this but I'm not sure. Thanks. scope_creepTalk 11:24, 28 April 2023 (UTC)Reply[reply]

A Google search and a working knowledge of chemical nomenclature leads me to the same conclusion as you: ethidene dichloride is 1,1-dichloroethane. "Ethidene dichloride" is archaic nomenclature, so it's hard to be 100% sure though. It's also possible that the actual product was an ill-defined mixture of closely related chemical compounds (which might include 1,2-dichloroethane, dichloroethenes, etc. in addition to 1,1-dichloroethane). Marbletan (talk) 14:36, 28 April 2023 (UTC)Reply[reply]
@Scope creep This Google book entry from 1884 has lots of hits for ethidene dichloride which confirm it is 1,1-dichloroethane. Mike Turnbull (talk) 20:02, 28 April 2023 (UTC)Reply[reply]

There is a requested move discussion at Talk:Aldol reaction#Requested move 21 April 2023 that may be of interest to members of this WikiProject. SkyWarrior 22:11, 28 April 2023 (UTC)Reply[reply]

Talk:Fire § Two things: seeking input. Also, Fire has been semi-prot for 13 years. Any feelings on whether it should be unprotected? -- (talk) 04:18, 29 April 2023 (UTC)Reply[reply]

This issue has been resolved, and did not require canvassing this WikiProject because it was so minor. I have filed an unprotection request at WP:RFPP, citing this discussion. –LaundryPizza03 (d) 06:57, 29 April 2023 (UTC)Reply[reply]
Said unprotection request has been declined, sorry. (talk) 21:26, 29 April 2023 (UTC)Reply[reply]

Separation process & List of purification methods in chemistry, merge/split? I think we should merge them.[edit]


捍粵者 (talk) 15:23, 30 April 2023 (UTC)Reply[reply]

FAC Nomination: Nonmetal (chemistry)[edit]

Please see here.

thank you, Sandbh (talk) 12:39, 2 May 2023 (UTC)Reply[reply]

Samarium at FAC[edit]

Wikipedia:Featured article candidates#Samarium

Sandbh (talk) 11:09, 7 May 2023 (UTC)Reply[reply]

RfC re periodic table[edit]

Editors interested in the categories and colors of the periodic table are invited to participate in a discussion at WT:WikiProject Elements § RfC on the classification of chemical elements on the periodic table. YBG (talk) 14:14, 24 May 2023 (UTC)Reply[reply]

The discussion about a periodic table with no colours was unanimously opposed and has been closed.

Discussion remains open on:

--- Sandbh (talk) 07:51, 31 May 2023 (UTC)Reply[reply]

Missing article: Poly-viscose[edit]

 – Pointer to relevant discussion elsewhere.

Please see: Wikipedia talk:WikiProject Textile Arts#Missing article: Poly-viscose.  — SMcCandlish ¢ 😼  02:11, 31 May 2023 (UTC)Reply[reply]


There is a requested move discussion at Talk:Per- and polyfluoroalkyl substances#Requested move 24 May 2023 that may be of interest to members of this WikiProject. ModernDayTrilobite (talkcontribs) 14:52, 31 May 2023 (UTC)Reply[reply]