Talk:Heavy metals

Article suggestions
I was asked to take a look. It's an interesting and well-written article. In addition to the modest edits I already made, here are some more suggestions.
 * 1. Too many quotes; these could be summarised.
 * Should be easy to fix.
 * Done.
 * 2. Perhaps a little too much discussion about the definition of the term. This will not be interesting to non-specialists, though it is interesting to me. --John (talk) 10:37, 28 March 2016 (UTC)
 * Might be OK as non-specialists can get the gist of it by reading only the first paragraph of this section, or only the first sentences in each paragraph of the section. Perhaps this one cld go through to the FAC jury.
 * 3. I'd also like to see more on the chemical (as opposed to physical) properties and uses of the substances, and on their biology. I'll be away for a few days so may not check this frequently. I will though. --John (talk) 23:12, 28 March 2016 (UTC)
 * I'll have another look at Duffus as he has some content on chemical properties, and biology. Did you have anything in mind with more on chemical uses? Catalytic applications comes to mind but apart from soaps, I'm not sure if the period 3+ metals have other shared chemical uses. (Not that I've thought much about this yet). Sandbh (talk) 10:22, 31 March 2016 (UTC)
 * On chemical properties I’ve added a paragraph in the definitions section about their behaviour as Lewis acids; electronegativity; and ionic or covalent bonding tendencies. For chemical uses I’ve expanded mention of their uses as anti-infective agents. As to biology, I’ve elaborated the nutrition section to show applicable biological processes for each of the named heavy metals.
 * Comparative properties table now added. Sandbh (talk) 23:16, 14 July 2016 (UTC)Sandbh (talk) 07:15, 9 April 2016 (UTC)

Shakey foundations
The article is premised on weak or non-existent definitions. Otherwise the lede or lede+1 would be loaded with high quality references. The opposite is found here. It is thus, in my opinion, a well intentioned OR project dressed up with a lot of jargon. If Wiki administrators or whatever want to evaluate important topics, they should first of all make damn sure that the topic is a topic, and not some loose term that caught some random editor's fancy. We all fall in love with topics and write a lot about them, me too, but that affection is not the foundation of an encyclopedic topic. Having said that, the article does no harm. --Smokefoot (talk) 13:26, 6 June 2016 (UTC)
 * There are good sources on this topic, as cited in the article: Nieboer & Richardson (1980); Hawkes (1997); Duffus (2002); Hübner, Astin & Herbert (2010). I believe it represents a fair overall summary and that the absence of a rigid definition has been appropriately noted. Sandbh (talk) 12:28, 8 June 2016 (UTC)
 * Quite so. Yet another high school essay masquerading as a scientific encyclopaedia entry, bandying the term 'heavy metal' about as the writer's whim takes him.

Selenium as heavy metal?
Sandbh, I can't help but wonder if things have gone astray. The list of essential elements includes some elements that are heavy metals and some that are generally not considered metals (except by astronomers). Going on to explain that some essential elements are nonetheless toxic at higher doses is an important point as well. But I question whether selenium belongs on this page about heavy metals. Is this an instance of WP:COATRACK? Aren't we supposed to confine ourselves to the putative subject of the page?  &#8212;jmcgnh  (talk) (contribs)  05:26, 20 June 2016 (UTC)
 * G'day Jim. Thank you for your question. I'm inclined to leave Se in, but I need to do a better job of explaining why in the article. I just noticed it doesn't appear in the density periodic table, yet I talk about Se in the toxicity and biological role section. Headslap! If you have a look at the metalloid article, here, you can see that Se is commonly regarded as a heavy metal in the environmental literature. Hence my reasoning. How does that sound? Sandbh (talk) 10:48, 20 June 2016 (UTC)
 * Admittedly, heavy metal gets thrown around fairly loosely at times. I guess you have to do a delicate balancing act between the different scopes of interest. And I see you're already involved in balancing content between here and Toxic heavy metal, so I think I'll just stand back and stay out of the fray.  &#8212;jmcgnh  (talk) (contribs)  20:07, 20 June 2016 (UTC)


 * Sorry, not good enough. This is supposed to be an encyclopaedia. These terms are being bandied about as though written by Humpty Dumpty. 'Heavy metal' is not a term you can define as the whim takes you.

FAC comments from Nergaal
''Copied from User talk:Sandbh I will have to go through it carefully again, but the intro is still on the too short side, and the source part in the second table still throws me off. The Goldschmidt classification article shows a different distribution. Nergaal (talk) 00:52, 7 July 2016 (UTC)
 * Thanks Nergaal. I think the intro succinctly captures all of the main body of the article but please let me know if there is anything you think I've missed.
 * Still short. Here are some ex I pulled form a quick search: "Many of the heavy metals, such as zinc, copper, chromium, iron and manganese, are essential to body function in very small amounts. But, if these metals accumulate in the body in concentrations sufficient to cause poisoning, then serious damage may occur. The heavy metals most commonly associated with poisoning of humans are lead, mercury, arsenic and cadmium. Heavy metal poisoning may occur as a result of industrial exposure, air or water pollution, foods, medicines, improperly coated food containers, or the ingestion of lead-based paints." or "The term has particular application to cadmium, mercury, lead and arsenic,[5] all of which appear in the World Health Organisation's list of 10 chemicals of major public concern." These might be a bit on the slightly too descriptive but some of the info should be explicit in the intro. Plus "heavy metals are useful in nearly all aspects of modern economic activity" is sooooooooooo vague. Give some explicit examples of common uses. Nergaal (talk) 01:20, 7 July 2016 (UTC)
 * Done. Sandbh (talk) 13:43, 8 July 2016 (UTC)
 * The second table shows the abundance and primary geochemical classification of the naturally occurring elements in the Earth's crust. The Goldschmidt periodic table shows the geochemical classification of the elements in the whole of the Earth, rather than just the crust, hence the difference. Does this help? Sandbh (talk) 01:05, 7 July 2016 (UTC)
 * I guess you could pull up the line into period 3 to go around the word litophile. But what about the f-block? The current scheme is not clear. Nergaal (talk) 01:13, 7 July 2016 (UTC)
 * Would adding some explanatory text at the bottom of the table fit the bill? Something like, "Heavy metals above and to the left of the dividing line (including those shown by the * and † symbols), are lithophiles; those to the right are chalcophiles, with the exception of tin and gold. Sandbh (talk) 02:01, 7 July 2016 (UTC)
 * OK I've done this. Sandbh (talk) 11:57, 7 July 2016 (UTC)


 * Legend for table 2: baby blue seems to be actually only up to 950.
 * I believe that was because the middle four legend boxes spanned two magnitudes each: 102 to 104; 100 to 102; 10–2 to 100 etc but I agree in this case it's misleading, so I've changed it to 999. Sandbh (talk) 02:01, 7 July 2016 (UTC)
 * Also, TBH, all the stuff in red and orange (plus Cd) in table 1 is what I think people think of when hearing HM. Anything in period 4 really seems like a stretch, so I would really like some clarification how and who see them as HM. Nergaal (talk) 01:09, 7 July 2016 (UTC)


 * Don't understand n14. Why not just say artificial and list stuff like Tc? Nergaal (talk) 22:37, 11 July 2016 (UTC)
 * They're not artificial since they do exist in the Earth's crust as a result of the radioactive decay of heavier elements. I originally left out Tc as the reference I was using had left it out of their geochemical periodic table. As I recall, Goldschmidt did the same with his classification of the elements. This kind of thing morphed into a discussion on my talk page, here, that Double sharp initiated and resulted in the non-listing of the rest of the ghost elements. Sandbh (talk) 12:38, 14 July 2016 (UTC)


 * "Atomic weight definitions start at greater than sodium (22.98) to greater than 40, or 200 or more" rephrase
 * "Definitions based on atomic number have been criticised for including metals with low densities." that guy said Rb explicitly should not be a HM?
 * No, that was my example of the point he was trying to make. He commented that some definitions refer to HMs having atomic numbers above 20, "that of sodium" [sic]. Obviously he meant to say "scandium". He then bags the inclusion of metals such as Mg and K as HM since they are essential metals and have densities lower than any that have been used as a defining property by other authors (as is the case with Rb, density 1.532 g/cm3). Sandbh (talk) 12:51, 14 July 2016 (UTC)


 * who is Hawkes
 * wikilink for class A/B
 * I've redlinked these terms as exisiting articles are restricted to inorganic systems only, and say nothing about biological systems. Sandbh (talk) 13:13, 14 July 2016 (UTC)


 * if some people dispute Ir, are there a specific set of metals that everybody strictly agrees are HM?
 * No. Maybe Hg and Pb would be close, with As (handicapped by its metalloid reputation), W, Tl and Bi as runners up. Sandbh (talk) 13:31, 14 July 2016 (UTC)


 * idea for intro: HM are relatively rare, but become a problem when concentrated as a result of industrial activities?
 * I think the expanded into does this?


 * "antimony can kill;" vague
 * "drug used to treat cancer," used to kill cancerous cells
 * " arsenic (metabolic growth in some animals, and possibly humans" needs citation
 * maybe mention dietary intake or estimate mg of HM in the human body? (i.e. how much Fe, Cu, Zn, etc)
 * I particulary like this one; will do some research. Sandbh (talk) 13:34, 14 July 2016 (UTC)


 * say that HM are abundant below the crust (Fe/Ni forms the core of Earth, U gives keeps it hot)
 * This one is good too. Sandbh (talk) 13:34, 14 July 2016 (UTC)


 * don't call Au "nobelest"
 * "became concentrated " => sunk
 * mention the term coinage metal
 * Mentioned in note 20, after the sentence that talks about HM use in coinage. Sandbh (talk) 23:38, 14 July 2016 (UTC)

Nergaal (talk) 23:06, 11 July 2016 (UTC)
 * who says actinides (U) are not heavy metals?
 * Striking a few done items. Sandbh (talk) 11:17, 14 July 2016 (UTC)
 * All done or addressed . Sandbh (talk) 23:38, 14 July 2016 (UTC)

more

 * I still think class A/B is a weird term Are you sure it doesn't refer to Patterson's classification of hard/soft bases? Anyways, a technical temr like this either needs to be explained or wikilinked to a real article. Nergaal (talk) 10:21, 2 August 2016 (UTC)
 * the biological role ca probably list the complete list of trace HMs with rough estimates (something like: Fe ~5g; Ni, Cu and Zn ~?mg; and Co?, Mn?, V?, Cr? as trace?) Nergaal (talk) 10:27, 2 August 2016 (UTC)

FAC comments from Graeme Bartlett
''Copied from Featured article candidates/Heavy metal (chemical element)/archive1
 * Is it possible to merge the "citations" and "references" sections as much as possible? They really only need to be distinct where there are more than one reference to different parts of the same work. It would be useful if there were many different pages from just a few books used for the whole article. As it stands it makes navigation to the actual reference extra complex, and for most of these there would be only one use any way. Graeme Bartlett (talk) 02:28, 7 July 2016 (UTC)
 * I looked back at the 116 citations and found that they and their references had been merged, where practical. If I was to use only a few sources the article would be a pale and patchy imitation. For example, Duffus addressed the definition question but his paper stops at 1936, and missed Hawkes' paper on what is a heavy metal. Habashi records the likely first appearance of the term but says nothing more about it. Emsley, and Tokar et al. discuss toxicity and biological roles but are sometimes incomplete (neither mention aquatic silver toxicity) or some of what they say was better expressed or illustrated by others, such as the lethal dose of nickel carbonyl. Cox addresses formation, abundance and occurrence but I found some of his writing to be hard going or lacking in clarity. The uses section relies on a fair number of citations from different sources simply because I couldn't find any better overarching sources. Sandbh (talk) 03:23, 10 July 2016 (UTC)
 * I've added a Further reading section as a way of focussing on some key works; there are a couple of additional coverage items there too. Sandbh (talk) 04:40, 11 July 2016 (UTC)


 * I will also investigate whether there are DOIs for some of those journals, and whether authors have article here on Wikipedia or not.

FAC comments by YBG

 * Density table - key It would be better if the key showed the colors in a single horizontal line instead of two columns. May need to put the numbers inside the colorboxes or under the colorboxes
 * ✅ YBG (talk) 05:06, 8 July 2016 (UTC)
 * I currently prefer the old version. The new version seems too colour-crowded. The old version, with discretly separated legend boxes, makes it easier for me to discern the colour categories. Sandbh (talk) 06:05, 8 July 2016 (UTC)
 * Yea, what I'd actually prefer is a small colorbox on one line with the legend underneath, but when I tried to do that, there was too large a space between the box and the legend. I'll give it another try later. YBG (talk) 06:38, 8 July 2016 (UTC)
 * I think it is better now. What say you? YBG (talk) 07:16, 8 July 2016 (UTC)
 * I agree. Perhaps space them out a bit more. Sandbh (talk) 02:47, 9 July 2016 (UTC)
 * ✅ YBG (talk) 03:47, 9 July 2016 (UTC)


 * Abundance table - key Similarly, better if the key were a single horizontal line. Need to put the numbers inside or underneath the colorboxes and might need to ditch the descriptions
 * I've modified this one like the second version of the table above. Comments? YBG (talk) 08:31, 8 July 2016 (UTC)
 * That's good. I would keep the other three descriptive labels, arbitrary as they are. Sandbh (talk) 02:47, 9 July 2016 (UTC)
 * ✅ (I had originally dropped them out 'cause I though they'd take up too much space.) YBG (talk) 03:47, 9 July 2016 (UTC)


 * Abundance table - Goldschmidt classification. There are three attempts to express this (1) the dark line (2) the text in the table and (3) the paragraph below. Yet despite this, it took me a long time to figure it out. I think I have a solution, and if I find time IRL I'll try to implement it.
 * ✅ YBG (talk) 06:38, 8 July 2016 (UTC)
 * I think this one may be better if we get rid of the f-block, and use Ln and An instead of where the * and † are now. The abundances could be averaged. The note explaining what's going on could mention the Tm and Pa exceptions. Sandbh (talk) 02:47, 9 July 2016 (UTC)
 * I'd be more inclined to use a 32-column table. We'd need to take up the whole page -- or notch the font-size down -- or both. YBG (talk) 03:47, 9 July 2016 (UTC)
 * I've simplified the way the dividing line works. Seems easier now. Sandbh (talk) 12:43, 9 July 2016 (UTC)
 * I like it -- especially the dotted lines. I did prefer having the dividing line separated from the lanthanides, would you mind if I moved it? And I notice you've reverted the legend, was that intentional? YBG (talk) 16:43, 9 July 2016 (UTC)
 * Please go ahead and move the line. I didn't happen to get to the legend so feel free to experiment with that. Sandbh (talk) 00:08, 10 July 2016 (UTC)
 * OK, I've moved the line and changed the legend. It's slightly different that I had before -- it goes from most- to least-abundant and has the descriptions above the colorbox and the ppm values below. But maybe they should be swapped? YBG (talk) 02:51, 10 July 2016 (UTC)
 * I think the descriptions should go below the colour boxes and above the ppm figures. I also think the original 3 + 3 layout looks cleaner than the 6 in a row layout, but let's see what the colour boxes below looks like. Sandbh (talk) 04:06, 10 July 2016 (UTC)
 * How does it look now? YBG (talk) 04:54, 10 July 2016 (UTC)
 * Comparing the 6 layout side by side with the 3 x 3, the 3 x 3 looks cleaner. Whereas the single row format for the top table works because the text accompanying the boxes is simple. As a bonus, the dividing line then doesn't appear to originate from the vicinity of the least abundant colour box. Sandbh (talk) 05:02, 10 July 2016 (UTC)
 * I've made two changes, which I'd like you to evaluate separately. (a) moved the *phile blurb above the color legends and (b) condensed the parenthetical comment re Au/Sn to avoid a line wrap, at least on my monitor. Comments? YBG (talk) 05:39, 10 July 2016 (UTC)
 * I've changed the table to show my final preferred layout: 3 x 3 colour legends (standard size blank boxes) followed by the blurb that now fits in two lines. See also my comment below. Sandbh (talk) 05:30, 11 July 2016 (UTC)

Hope to provide more input later YBG (talk) 00:01, 8 July 2016 (UTC)
 * Abundance table: header I rephrased this so the primary topic (heavy metals in the Earth's crust) comes first. (this wouldn't matter if it all fit on a single line.) Also, this appears as two colspan=20 rows, would it be better as a + header row? YBG (talk) 16:43, 9 July 2016 (UTC)
 * The rephrasing is nearly perfect! And "abundance" should be Abundance. The header appears on two rows as it is too long too fit on one row and dividing it into two rows is the only way that I could see of centering both parts of the title. Sandbh (talk) 01:32, 10 July 2016 (UTC)
 * OK, rephrasing is done. What do you think about changing it to a + header row? It is the more standard method of showing a table header. If you like, I could change it to see what it looks like. YBG (talk) 05:30, 10 July 2016 (UTC)
 * Pls proceed. Sandbh (talk) 05:44, 10 July 2016 (UTC)
 * OK, I've done it. I eliminated the hidden footnote markers which showed up when you dragged through the header. But the first note really belongs with the first line, so that balances it out a bit. Not sure we still need the first empty row; if so, it would be better implemented as a table-level style. YBG (talk) 07:33, 10 July 2016 (UTC)
 * As per my above comment the table now appears in my final preferred style. There is no only one (three part) table heading footnote. The hidden footnote maker is still there for centering purposes. It should not show unless you look at the code. I like the fact that for both tables, the legend box layout is tailored to suit the information being presented. Sandbh (talk) 05:30, 11 July 2016 (UTC)
 * OK, I'll give up on the color swatches.
 * But the hidden footnote marker, IMHO, actually destroys the centering. This is particularly obvious in the first chart, where there is almost no right-hand margin (between the end of the marker and the edge of the table), but a large left-hand margin (between the beginning of the header and the left edge of the table. I understand that you are trying to center the header-sans-note-markers, but visually, the note markers are more similar to the header than they are to the white space. I'm no graphic designer, so perhaps you should ask someone with more experience in graphic design. Why not put the footnote markers on their own line? The extra white space might actually improve the overall appearance negative-space-wise.
 * I've removed the hidden footnote markers, as requested. Sandbh (talk) 02:09, 16 July 2016 (UTC)
 * And at some point in time, we'll need to deal with accessibility issues. Blind people use WP, but they would find much of WP:ELEMENTS difficult to use, but that is a much bigger issue that we can deal with right now. It was part of the reason I preferred +. The shading/border could be set so that the appearance is nearly the same as it is now, if desired, but I think the standard method of presentation is for the header to be outside the table shading and border.
 * Still need to get back to you on this one. Sandbh (talk) 02:09, 16 July 2016 (UTC)
 * Oh, and by the way, is the en-au gerund really "centering"? YBG (talk) 07:37, 12 July 2016 (UTC)
 * Heh. In Australia, one should write "centring", which I would if I used it in the article, but in casual conversation I prefer the US spelling in this case (this is even included in our national dictionary but is noted to be a US spelling). Sandbh (talk) 02:09, 16 July 2016 (UTC)


 * Occurrence or source Header says "main occurrence or source"; footer says "occur or are mainly sourced". Does "main" apply to one or to both? Should we conflate occurrence and source? Or maybe it would be better have the *phile classification concentrate on source (maybe by using the term 'ores') and relegate the details to footnotes. These suggestions are confusing and may actually be suggesting something that is not correct, but that generally reflects the fact that the notes at present are, at least for me, a bit confusing and hard to understand. YBG (talk) 16:43, 9 July 2016 (UTC)
 * The "main/mainly" applies to both so I've edited the footer to this end. You're right about the notes so I've removed these for the sake of clarity. Sandbh (talk) 01:32, 10 July 2016 (UTC)
 * It looks like this might have been overwritten or not saved. Could you check it again?
 * It should be OK now? Sandbh (talk) 05:44, 10 July 2016 (UTC)
 * Better, but unfortunately, to me it seems like 'mainly' might only apply to 'occur'. What about changing it to say "are mainly found as lithophiles". "Found" is neatly ambiguous, covering both occurrence in general and source in mining. YBG (talk) 05:48, 10 July 2016 (UTC)
 * How does last change look? Sandbh (talk) 05:56, 10 July 2016 (UTC)
 * Great except for re-introducing the wrap onto a third line. Sigh. YBG (talk) 07:33, 10 July 2016 (UTC)


 * Tungsten border It displays OK, but there's something funny in the wiki markup -- looks like the bottom border has two colours specified. I tried to fix it but the preview didn't look right, so I didn't save it. YBG (talk) 16:49, 9 July 2016 (UTC)
 * ✅ Turns out there was some weirdness in the previous elements. Lu still looks like it is a bit lower than the others (when I look at 250% magnification), but it seems that the other yellow cells seem to be the same. The styles are identical except for the background colo(u)r, so my current theory is that it is an optical delusion. Anyway, I'm done looking cross-eyed at cell boundaries. At least for now. YBG (talk) 05:30, 10 July 2016 (UTC)
 * It does look better now. I think its a delusion---Se looks too small but it isn't really. Sandbh (talk) 05:56, 10 July 2016 (UTC)

lede== ===

YBG (talk) 06:48, 12 July 2016 (UTC)
 * Start with a squishy definition, something that gets at the commonality of all of the definitions without mentioning any of them, maybe something as simple as "relatively heavy compared to other metals"
 * Then finish ¶1 with either
 * either (a) all of the definition stuff from /*top*/ (density, AW, Z, and the stuff from ¶2)
 * or else (b) all of the toxicity stuff from ¶1
 * ¶2 should have (b) or (a) whichever wasn't in ¶1
 * The toxicity stuff as it now stands doesn't seem to be a coherent whole, no clear organization between the sentences. Whether this stuff ends up in ¶1 or ¶2, it needs to be organized better
 * ¶3 - "useful in nearly all aspects of modern economic activity" and "general, specialised and niche uses" don't seem to contribute very much. Maybe just use the list or a portion of the list. I don't think the list needs to be a complete review of what is said in the article, the main point is to list enough to demonstrate just how varied and widespread HM use is. Maybe a couple of extremes -- high/low tech; everyday/specialized; or the like
 * Comments to follow soon, including re the previous section (catching up from doing the properties table, and addressing Nergaal's comments). Sandbh (talk) 23:40, 14 July 2016 (UTC)
 * Thank you YBG, that was good feedback.


 * The original definition, here, was simpler. The current definition is an outcome of feedback I rec'd from R8R Gtrs (who asked for the context bit) and Nergaal (who asked for more on toxicity) during the FAC process, here. It now represents the commonality of the most common definitions. I understand your intent but saying something like "relatively heavy compared to other metals" lacks meaning i.e. what does the "heavy" mean, and is unfortunately similar to the response Hawkes got when he asked his teacher "What's a heavy metal?", and was told, "A metal that behaves like a heavy metal".


 * I did however edit and trim the lead (and adjust the toxicity section of the article) in light of the rest of your feedback. It reads better now and more closely follows the structure of the main body of the article, and that is a good outcome I reckon. Sandbh (talk) 01:51, 16 July 2016 (UTC)


 * Yes, it reads much better now. Do you think we need to say 'depending on context'? And which would be better -- 'more specific definitions' or 'more precise definitions'? YBG (talk) 03:02, 16 July 2016 (UTC)
 * "Depending on the context" is a more common expression than "depending on context" so I'll keep the former. For specific or precise I had a look in the OED, as i couldn't tell the difference from looking in the Macquarie dictionary. Here are extracts of the two entries:


 * Specific. 1a. Having a special determining quality b. Having the quality of a species (obs); 2. a Of qualities, properties, effects etc; Specially or peculiarly pertaining to a certain thing or class of things and constituting one of the the characteristic features of this. c. Peculiar to, characteristic of something.


 * Precise. Definitely or strictly expressed; exactly defined; definite; exact; of a person, definite and exact in statement. b. Of an instrument: Exact, accurate. Obs. c. Of the voice or tone: Distinctly uttered. 2. Strict in the observance of rule, form, or usage; formal, correct, punctilious, scrupulous, particular; sometimes, Over-exact, over-nice, fastidious. Also of a practice or action: Strictly observed...3, Exact; neither more or less than; perfect, complete: opposed to approximate.. 4 Distinguished with precision from all others; identified, pointed out, or stated with precision or exactness; the precise, the particular, the identical, the very, the exact.


 * This confirms my impression that more specific is the better expression (more precise seems too much like a redundant expression to me). Sandbh (talk) 09:59, 17 July 2016 (UTC)


 * Regarding "Specific" vs. "Precise", I didn't have a strong sentiment either way, just a concern that both be considered, which you've done admirably, thank you.
 * Regarding "depending on the context" Re-reading my post, I realize my careless typing made you jump to the wrong conclusion. I agree that "depending on the context" reads better than "depending on context". But I was not suggesting removal of "the" but rather removal of the entire clause. As it stands now, the lede sentence includes two parenthetical (appositional?) phrases in what should be a simple sentence of the form "A (term being defined) is a (generic category) that (defining characteristics)". In WP:LEADSENTENCE, it says
 * If its subject is definable, then the first sentence should give a concise definition: where possible, one that puts the article in context for the nonspecialist.
 * Try to not overload the first sentence by describing everything notable about the subject. Instead use the first sentence to introduce the topic, and then spread the relevant information out over the entire lead.
 * To these, I would add
 * Try to not overload the first sentence with all of the exceptions to the general rule. Instead use the first sentence to state the general rule, and then include the exceptions in the second sentence or later in the lead as appropriate.
 * We're doing well in the two points I've quoted from the MOS, but not so well in my addition, which strives as the spirit of the 2nd. I believe the lede sentence would be better if we could avoid both parenthetical comments; with one or the other, it would be OK, but with both of them it overwhelms the definition. YBG (talk) 21:13, 17 July 2016 (UTC)
 * Right then. How does it look now? Sandbh (talk) 23:16, 18 July 2016 (UTC)
 * The opening sentence is great. I'm going to try my hand at simplifying and/or combining the 2nd and 3rd sentences. YBG (talk) 02:03, 19 July 2016 (UTC)
 * Good luck with that; it will be hard to combine these two into a single pleasing sentence. Sandbh (talk) 03:14, 19 July 2016 (UTC)
 * Does this work? YBG (talk) 06:07, 19 July 2016 (UTC)
 * Superbly! I just fine tuned it. Not sure yet if the em dashes shouldn't be commas. Sandbh (talk) 06:50, 19 July 2016 (UTC)

A well-deserved break
Thanks for working with me on sentence 3. What do you think about this:
 * More clear-cut definitions have been published, including those based on specific chemical behaviour or periodic table position, but none have obtained widespread acceptance.

Thoughts? YBG (talk) 04:08, 20 July 2016 (UTC)
 * "Clear cut" struck me as too much like "precise," and we don't need to say this and use "specific" later on. I like tne trimming you did on the second half of the sentence. So, "More specific definitions have been published, including those based on chemical behaviour or periodic table position, but none have obtained widespread acceptance." works for me. Sandbh (talk) 09:57, 20 July 2016 (UTC)
 * In retrospect the "these", as in "none of these have obtained" should be kept, to show that while HM are usually regarded as metals having high density etc, it is only the more specific proposed definitions that have not obtained widespread acceptance. It's messy. Sandbh (talk) 01:39, 23 July 2016 (UTC)
 * What about "none of these definitions"? YBG (talk) 03:28, 1 August 2016 (UTC)
 * Or how about just "none"? Sandbh (talk) 03:32, 1 August 2016 (UTC)
 * Maybe. The key problem is that there are too many possible antecedents. YBG (talk) 04:08, 1 August 2016 (UTC)
 * Ah, I see. Changed as per your suggestion (I balked at it initially due to the sentence ending up with two "definitions"). Sandbh (talk) 08:02, 1 August 2016 (UTC)
 * If we could elegantly merge all of the definition options -- which measure of heaviness, whether to include metalloids/alloys, etc -- into one complex clause, talking about properties in one place and definitions in another -- then it might be possible that a bare "none" would have a clear antecedent. But my head is starting to spin. YBG (talk) 06:52, 2 August 2016 (UTC)

Pie chart
So, there was no mixed metaphor that I could see. I'm not a fan of pie charts except in limited cases; this one took up way too much room and the HM slice was indistinguishable. The metaphor is more powerful and does it in a fraction of the space. Sandbh (talk) 09:07, 17 July 2016 (UTC)
 * I'm not terribly fond of that particular pie chart either, but I thought it needed something.
 * The current metaphor has several problems, not the least of which is is the clash of comparing 1-dimensional time fractions to 3-dimensional mass fractions. Then there is the problem of using words and phrases like "translate" (which sounds linguistic) and "last for" (which made me first think of half-lives). I would prefer a comparison that said, for example, that the weight of metals corresponds to the weight of one hand and one foot, and heavy metals to to a few teeth. That sure sounds different than either the current metaphor or the reverted pie chart, so maybe I've got the proportions wrong. But something of that sort would be much more meaningful than either time fractions or a pie chart. YBG (talk) 21:58, 17 July 2016 (UTC)
 * LOL! Let me think about that one over breakfast :) Sandbh (talk) 23:30, 17 July 2016 (UTC)
 * I changed the metaphor into weight equivalents. How does it look now, bearing in mind these can only be approximate? Sandbh (talk) 01:41, 18 July 2016 (UTC)
 * Dried peas and a bottle of wine doesn't seem like a traditional breakfast, but the washing machine is really stretching it. Seriously, though, the washing machine doesn't obviously match the size of our hypothetical 1 70kg human. I still think using actual body parts would be best and most easily put into perspective. YBG (talk) 01:59, 18 July 2016 (UTC)
 * As you note, the idea is to give the reader a feel some mental hooks for putting the weights involved into perspective . Body parts won't do as very few people would know how much individual body parts weigh. Most people would appreciate how much two dried peas or a bottle of wine would weigh. And I've moved a few washing machines in my time and I can remember my dad doing the same. BTW our hypothetical standard elemental human weights only 70 kg (150-odd lbs). Sandbh (talk) 03:15, 18 July 2016 (UTC)
 * I knew obesity was an expanding problem, but I had no idea ....
 * First thing to decide is what is the most important thing we are trying to communicate by metaphor - the absolute mass of HM and LM and NM in the human body, or their relative proportion. All of my suggestions have been based on the latter assumption, as that seemed the main point of the the clock metaphor.
 * How about something like this: 7 gr of heavy metals weighs about as much a wine cork or the tip of a finger; 1.4 kg of light metals, about as much as a bottle of wine or the rest of the hand and forearm almost to the elbow. The nonmetals would comprise the rest of the human body if the heavy and light metals could be concentrated in the hand and forearm.
 * This is based on a 2cm×2½cm×1½cm fingertip (my own index finger) the density of water (a wild guess) and 0.66% hand and 1.6% forearm (from a probably non-WP:RS).
 * YBG (talk) 04:32, 18 July 2016 (UTC)
 * I thought about saying something about the hand holding the wine bottle, but that seemed a bit much. YBG (talk) 04:42, 18 July 2016 (UTC)
 * I changed what the idea is (above), from a mental hook, to a feel for the weights involved, which is what I should've said in the first place. I like the thought that went into your suggestion. The issues I have with it are that it takes twice as much wording to explain what is said in the lead sentence i.e. "A standard 70 kg human being is composed of around 7 gm (~0.01%) of heavy metals, 1.4 kg (~2%) of light metals, and nearly 68.6 kg of nonmetals (~98%)". This is not good. I also think that if it takes two "analogies" apiece to explain then this is not good either. And to pick up on something you triggered in me, I started thinking of a tip of finger, or the rest of a hand almost to the elbow etc as volumes, as if our standard person was a glass being filled up with a fluid measure, rather than as weight equivalent illustrations. Concepts such as a tip of a finger and an arm up to an elbow convey no real life feelings in me for the weights involved. Yes, we are trying to give an idea of the relative proportions by weight. I was going to finish by saying something clever about washing machines but looked up the weight of my washing machine instead. It's 73 kg. Sandbh (talk) 07:36, 18 July 2016 (UTC)
 * Yea, I agree, using fingertips and forearms does make it seem like volumes, so I was just replacing one mixed metaphor (time) for another (volume). Sigh. How about this:
 * An average 70 kg human being is composed of about 0.01% heavy metals (~7 gm, the weight of two dried peas) and about 2% light metals (~1.4 kg, the weight of a bottle of wine), with nonmetals making up the remaining 97.99 98 %.
 * I think we can safely jettison the washing machine, I'm not sure it adds much. Or actually, it adds too much -- 4.407kg too much. YBG (talk) 02:43, 19 July 2016 (UTC)
 * Brilliant! Please proceed. I will shed a tear for the washing machine. Sandbh (talk) 02:48, 19 July 2016 (UTC)
 * I've used the 97.99, though I don't like the false precision. Do you know whether Emsley gives the percentages or the kg/gr? YBG (talk) 03:01, 19 July 2016 (UTC)
 * He only gives the weight for each element. I added "or so" after the 97.99 to make it less precise. Sandbh (talk) 09:40, 19 July 2016 (UTC)

Uses
Further to your earlier comments about general, specific, niche etc I'll see if I can re-sort these uses into something like (in no particular order yet): 1. Manufacturing and construction; 2. Density based applications; 3. Atomic number based apps; 4. Colouring agents; 5. Biological agents; 6. Soaps; 7. Catalysts; and 8. Electronics and electrical. This may take a while. Sandbh (talk) 02:56, 19 July 2016 (UTC)
 * This has been done (at last), except that there are only seven major usage categories rather than eight. Some fine-tuning to follow. Sandbh (talk) 11:11, 29 July 2016 (UTC)
 * I notice that the sub-sections of fall into two different groups
 * Economic sectors:
 * §§ Biological science * Chemistry * Manufacturing and construction * Nuclear science
 * HM properties (or properties + sectors):
 * §§ Colouring agents, glasses, ceramics * Density-based * Electronics, magnets, lighting
 * I'm just wondering it this observation might be of some use. For example, might it be cleaner if the classification was all one way or the other? For example, if the section headings were all based on what property it is that makes HM economically useful, with the section text mentioning the economic sectors. I notice the M+C§ includes coinage, showing that the real topic is how HM provide structure, large and small. The Usage summary § could summarize both the different useful properties of HM and also list the economic sectors in which they are used.
 * Here's one idea: Biological agents * Chemical agents * Colouring agents * Density agents * Electromagnetic agents * Structural agents * Nuclear agents
 * Some of those are admittedly a stretch, but you get the idea. Other possibilities are such things as "Providing colour/density/structure"
 * In a related note, the complex last paragraph in the lede section is somewhat confusing with the comas-within-semicolon structure. Not sure what to do about that right now, maybe something will come to mind. YBG (talk) 04:07, 1 August 2016 (UTC)
 * I think I'm currently torn between supporting a cleaner classification schemes versus one which uses pragmatic plain English labels. The current labels are indeed based on the properties that make HM's useful it's just there is no economic sector governing e.g. density-based applications of heavy metals. The applications in question go across too many sectors. I suppose you could say "Sporting and Engineering" rather than Density-based; just "Ceramics" rather than Colouring agents, glasses, ceramics; and "Electromagnetics," rather than Electronics, magnets and lighting, but at least the latter two aren't real economic sectors, AFAIK. And all three alternatives lose plain-English points. If something good comes of this, fine but it needs more time in the oven for now. The last paragraph of the lede will be hard to fix without generating cognitive dissonance between whatever it says and the table of contents right after it, with its "huge" Uses section and subsections. Sandbh (talk) 10:36, 2 August 2016 (UTC)
 * The complex last sentence of the lede has been fixed, I hope. That was a good call, thank you. Sandbh (talk) 03:04, 3 August 2016 (UTC)
 * Thanks, it is much better now. 05:01, 3 August 2016 (UTC)

Here's another try at reorganizing the usage sections. Thoughts? YBG (talk) 05:01, 3 August 2016 (UTC)
 * Start with the longer sections, the ones intrinsically related to the heaviness of heavy metals
 * Density-based uses
 * Strength-based uses (formerly manufacturing & construction)
 * Proceed to the shorter sections re more specific uses
 * Biological and chemical uses (combined sections, moving batteries down to electronics)
 * Colouring and optics (expand by including reflectivity from Manufacturing & Construction)
 * Electronics, magnets and lighting
 * Nuclear uses
 * This appears to have high potential! Will look again in an hour or so, I hope. Sandbh (talk) 23:28, 3 August 2016 (UTC)
 * Your edits look good. At first, I was disappointed about the removal of "uses" at the end of several subsections, but after re-looking at the TOC, I think it is better without. Thanks! Nevertheless, I'm still not 100% convinced about "resilience".
 * One more thought: there's some stuff re nuclear shielding at the end of the density section that maybe could be moved down to the nuclear section. Just a thought. YBG (talk) 07:09, 4 August 2016 (UTC)
 * Yes, your suggestion was "just so", which is high praise in my book. I had to say "resilience" to cover metals like zinc, tin and lead all of which are low strength but which have high corrosion resistance and are used in that context. Reslience was the only word I could think of that captures physical strength as well as endurance against chemical attack strength. I still need to get back to you on metalloids in the human body and the nuclear shielding example. And perhaps to give some zinc, tin and lead examples. Sandbh (talk) 07:17, 4 August 2016 (UTC)
 * It was your prodding that forced me to keep thinking until I found some plain English that works -- i.e. avoiding the overuse of "agents" that was the hallmark of one of my thankfully deep-sixed suggestions.YBG (talk) 08:05, 4 August 2016 (UTC)
 * Googling around, "resilience" seems to be close to appropriate, at least contemporaneously: (1); (2). Sandbh (talk) 07:45, 4 August 2016 (UTC)
 * Don't loose any sleep over it. Resilience may grow on me.
 * And to continue my rant about plain English: I've been trying to come up with a substitute for "pervade many aspects of economic activity" and "pervade nearly all aspects of modern economic activity". Is this in contrast to non-economic activity? Or does it simply mean all areas of human life? The key concept to get across is the contrast between their rarity in the ground and their widespread use. Which reminds me about another thing I've been ruminating over. Is there a better way to express this without using "Earth's crust". I don't think they are all that more abundant in the rest of the lithosphere (mantle and core), much less the hydrosphere or atmosphere (to list some more words that I don't want to use). And what about replacing "artefact" with something a bit less pretentious. (I hope I'm not just saying this 'cause of the red underline supplied by my en-us spell checker.)
 * None of these are show-stoppers by any means. Just want mentioning them so that we'll both be thinking about it. YBG (talk) 08:05, 4 August 2016 (UTC)
 * Well, resilience has gone away :) because I think "Strength" is broad enough to encompass what I was trying to say with resilience. I did have a look earlier on about the stuff re nuclear shielding at the end of the density section as, like you, I wanted to see if it was a better fit in the nuclear science section. I concluded that the shielding etc applications were more density-based rather than atomic number based, so I left them in the density section, and I added the comment about their being some overlaps between the different usage sections/categories. Sandbh (talk) 03:19, 5 August 2016 (UTC)
 * Here is what Provenzano says about HM and economic activity: ""HM impart economic benefits to virtually every kind of economic activity. The advanced technology of our mass production economy is highly dependent on the physical and chemical properties of their materials." (p. 339). Does that help? The Earth's crust is important since that's where we source HM from; bringing the rest of the planet into the picture is irrelevant and would be misleading. I changed artefact to product even though I think artefact is a more precise word, given its meaning of, "Anything made by human art and workmanship; an artificial product." (from the OED). But I'll see if I can live with mere "product". Sandbh (talk) 03:39, 5 August 2016 (UTC)
 * Re economic activity: When I hear this phrase, I think primarily of buying and selling, then I jump to employment. But then I think, what's left? Not hobbies, because hobbiests buy stuff at stores. Not home and family life, because we're we're all consumers. Volunteer activities? Don't get me started about how wikieditors are dependent on all sorts of HM in high tech equipment. In short, I'm not sure I see any aspect of human activity that would not be classified as "economic activity" and even if there were some "non-economic activity", I suspect it would be just as dependent on HM. So although our WP:RS uses the term economic activity, I'm not sure it adds much to our article.
 * Changed to "present in modern life". Sandbh (talk) 01:29, 6 August 2016 (UTC)
 * Re earth's crust: Yea, I know HM aren't mined in the core or the stratosphere, but what does it add other than unnecessary jargon? Could we use something more non-technical like "ground"?
 * And at the risk of repeating myself, I'd really like to emphasize the contrast between the scarcity of HM in the ground with the pervasiveness of their use - and usefulness - in all aspects of modern life. YBG (talk) 06:47, 5 August 2016 (UTC)
 * Mention of the crust in the lede occurs because we talk about the crustal abundance of heavy metals in the Formation, abundance and occurrence section. For a technical article I think this is appropriate terminology. On scarcity etc the lede says, "Heavy metals are relatively scarce in the Earth's crust but pervade many aspects of economic activity." and later on we say, "Light metals (~20%) and non-metals (~75%) make up the other 95% of the crust.[71] Despite their overall scarcity, heavy metals can become concentrated in economically extractable quantities as a result of geological processes (such as mountain building or erosion).[80]" Do these extracts not address your concerns re scarcity v pervasiveness?

Links

 * Classification of metal ions in biochemistry 3×, pipelinked as "class B", "borderline metals", and "class A metal ions"
 * Ambivalent ions
 * Nuclear shadowing pipelinked as "shadowing"
 * Nuclear shadowing pipelinked as "shadowing"
 * Nuclear shadowing pipelinked as "shadowing"

(blue links to follow) YBG (talk) 02:29, 20 July 2016 (UTC)
 * (Not sure what I was going to do with blue links -- except maybe look for redirects. YBG (talk) 01:34, 8 August 2016 (UTC))
 * These still need fixing. YBG (talk) 06:26, 7 August 2016 (UTC)
 * Redlinks are OK, are they not (WP:RED)? Sandbh (talk) 09:09, 7 August 2016 (UTC)
 * I presumed that these topics were already covered someplace at WP. If the articles ought to exist but do not yet exist, then they're OK. If you the non-existent article names are the best ones for this info, then they should be left red. Or perhaps create a stub article? Anyway, if you've already considered this and have determined that the current red-link situation is the best it can be for now, and there is now need to fix redlinks for the current FAC, then I'm fine with it as it is. YBG (talk) 01:34, 8 August 2016 (UTC)
 * Agree; NFA required. Sandbh (talk) 01:31, 9 August 2016 (UTC)

More
There are several places where a mini-PT illustration might be helpful, like we used at Properties of metals, metalloids and nonmetals. Particularly where there are lists of elements. YBG (talk) 06:55, 2 August 2016 (UTC)
 * I tend to think not, but I may be wrong. Certainly, for Uses, for I've tried to spread the examples across the transition metals, post-transition metals, metalloids, and lanthanide/actinides so all we would tend to get would be tables with elements scattered across these sections. I find the mini-PTs used in Properties of metals, metalloids and nonmetals suffer from repetition. Visually, the massed effect is not pleasing. Sandbh (talk) 10:52, 2 August 2016 (UTC)
 * Yea, I can see how it isn't particularly exciting visually. But for me, when I see an element I'm not familiar with, my first thought is "where is it in the PT?" I suspect that others might be helped similarly. But clearly it is less helpful here than in PMMN. There, we are showing all elements that share some unique property, and there is no editorial discretion re which elements to list. Here, we are listing selected examples, and there is a great deal of editorial discretion as to which examples we use. Consequently, the positions on the PT are not as significant nor as helpful in this article. YBG (talk) 07:20, 4 August 2016 (UTC)
 * Even in PMMN I don't like how it looks, but I recognise that the reason I don't need it is because I've memorised the entire PT (spend enough time in chemistry and you'll manage it), so it really helps those who haven't. Although I think perhaps it would be better even there as a single custom image, in which only the elements singled out for discussion are named and highlighted. Double sharp (talk) 15:18, 6 August 2016 (UTC)
 * OK, YBG (talk) 06:26, 7 August 2016 (UTC)

Definitions
✅
 * Why "may be" and not "is"?
 * It's a bit hard to be too assertive about heavy metal definitions even within the same discipline so I play it safe with "may be".
 * "Are known or have been used" seems needlessly wordy.
 * The US Pharmocopeia definition has been applied in practice but I don't know for sure if this is the case with Hawkes' effort.
 * Need to fix redlinks
 * As per my other comment I suspect this is not so but will wait to hear from you on this.
 * "Along with definitional looseness" reword to get rid of "definitional", maybe "Adding to the confusion of multiple definitions" or something else.
 * I think "definitional looseness" captures what I'm trying to say concisely, and "definitional" seems to be an OK word i.e. I can find other examples of it and "definitional looseness", but I'm not stuck on either. Sandbh (talk) 11:55, 7 August 2016 (UTC)
 * OK, I'm fine with this all -- although when I read through the whole article, I'm struck by an over-abundance of "may be" and similar language. The individual instances aren't necessarily a problem, but taken together, it seems an overwhelming overload. Consequently, the more of the individual ones that can be eliminated, the better. I leave it to you to figure out how many and which ones to change. YBG (talk) 01:53, 8 August 2016 (UTC)
 * I've changed about a third of these to something else. There are probably still too many conditional expressions for your taste but that's the nature of this beast. Sandbh (talk) 03:47, 9 August 2016 (UTC)
 * Not sure changing half the "may be"s to "might be" makes that much difference. I do like what you did to the lede, but I wonder if it would be possible to say "is usually defined" or "is often defined" instead of "may be". YBG (talk) 06:48, 9 August 2016 (UTC)
 * I can be more assertive about chemistry but in metallurgy and physics the interest in density or atomic number sometimes crosses over and the number of metallurgy- and physics-based sources referring to heavy metals are too few to be more assertive IMO. Sandbh (talk) 10:23, 9 August 2016 (UTC)

Toxicity
✅
 * "Some heavy metals" -- missing comma at end of appositional list of elements
 * Done, tx.
 * Why "potentially hazardous" and not just "hazardous"
 * It seemed wrong to say that Cr, for example, is hazardous when that could only be said of hexavalent Cr.
 * OK, point taken. YBG (talk) 01:53, 8 August 2016 (UTC)
 * "... due to the toxicity of some of their combined or elemental forms" Why not "... because the pure element or some of its compounds are toxic"
 * I can't say this easily because e.g. while Hg vapour is toxic, liquid Hg isn't particularly toxic hence the reference to elemental forms. And I like having the "toxic" word at the front rather than at the end.
 * What about changing the sentence to begin with "Due to the toxicity of specific compounds or elemental forms, some heavy metals are potentially hazardous, especially ...." (thus eliminating the need for the 2nd coma you so kindly added :) YBG (talk) 01:53, 8 August 2016 (UTC)
 * The sentence becomes too long-winded, with the most important message coming at the end. It's not worth it for the sake of a comma. Sandbh (talk) 10:55, 8 August 2016 (UTC)
 * Actually, that is part of the reason I like the change, because keeps the important stuff at the beginning and moves the list of elements to the end. Mentioning the coma was only my attempting to be funny. YBG (talk) 23:39, 8 August 2016 (UTC)
 * Although I'd like to see the important info before the long list of elements, I don't see a good way to do that. YBG (talk) 01:50, 22 August 2016 (UTC)
 * "Heavy metals essential for life (see next section) ..." Change to "Even heavy metals essential for life" and drop parenthetical phrase, replacing with wikilink if desired.
 * "Even…" seems to too dramatic to me. I haven't put a wikilink here because the topic is discussed in the next section and I wanted to flag this hence the parenthetical comment. That was a tough paragraph to write because I was introducing an out of context concept i.e. essential elements in the toxicity section. I thought the (comment) was a short way of reassuring the reader, and not disrupting the flow.
 * Although I'd like to eliminate the "(see next section)", I can't figure out a good way of doing that right now. YBG (talk) 01:50, 22 August 2016 (UTC)
 * 5g Fe - maybe mention that the number of grams of Fe normally in the human body here? No, probably not, unless it can be done without destroying the flow.
 * Agree: maybe not.
 * I've added the iron factoid in parallel the info re selenium. YBG (talk) 01:50, 22 August 2016 (UTC)
 * "A few other non-essential heavy have one or more toxic forms." Non-essential makes this paragraph clearly contrast with the previous paragraph (#2) Is this a continuation of paragraph #1 or is there some distinguishing feature between P2 and P3? It may be better to move P2 to the end so that the paragraph about the hazards of large intake of otherwise essential HM would provide a good lead-in to the following (Biological role) section.
 * I'll look closer at this as the flow of the toxicity section doesn't match the summary in the lead. Sandbh (talk) 12:43, 7 August 2016 (UTC)
 * Right then. Having looked closer at the history of the lead, I'm OK with the match up between the lead and this section. The toxicity section is structured as follows, P1: The "notoriously" toxic HMs; P2 and P3: The relatively harmless HMs, divided into (P2) those that are essential but can be toxic in excess or in certain forms; and (P3) those that are non-essential, hence less scope for being taken in excess, but which have one more toxic forms one may not have heard of. I think the separation between P2 and the following section is about right: neither too far nor too close. Sandbh (talk) 01:56, 8 August 2016 (UTC)
 * Your explanation here is very helpful in explaining the reason why P1 and P3 are separated. Any way to make it clear that P1 HMs are notorously toxic and P2 and P3 are relatively harmless but still potentially dangerous? YBG (talk) 02:09, 8 August 2016 (UTC)
 * I divided this section into subsections and I think this may have done the trick. Sandbh (talk) 01:24, 9 August 2016 (UTC)
 * Yes, this makes it much better. YBG (talk) 01:50, 22 August 2016 (UTC)

Biological role
✅ Biological role
 * Maybe change section title to "Essential biological role"? The previous section about toxicity is also a biological role, though a strictly negative one.
 * I took the section titles from those used in the various element articles i.e. Biological role, and Toxicity. See Nickel for example.
 * "... some animals, and possibly humans" Is this comma needed?
 * Yes, to make it clear that the "some" only applies to animals (this is the way the source expresses it), whereas if As was essential it would presumably be so for all humans.
 * Got it. I've changed it to "in some animals and possibly in humans", which I think is better. YBG (talk) 04:52, 8 August 2016 (UTC)
 * "This is consistent with ..." This sentence seems like it could be simplified.
 * Please go ahead. I've expressed it the way it is because the source only states it as a presumption.
 * OK, here is the text as in currently exists:
 * There are not many essential heavy metals in periods 5 or 6. This is consistent with the incidence of essential trace elements tending to be related to their abundance (heavier elements tend to be less abundant).
 * Here is one possible rewording of these two sentences:
 * Periods 5 and 6 contain fewer essential heavy metals, consistent with the general patterns that heavier elements tend to be less abundant and less abundant elements less likely to be nutritionally essential.
 * How's that? It's not much shorter, but to me it seems to be clearer. YBG (talk) 01:13, 22 August 2016 (UTC)
 * I'm just going to boldly make the change. YBG (talk) 06:36, 22 August 2016 (UTC)
 * "A deficiency of ..." This is a fascinating factoid! Maybe emphasize this as follows: "A deficiency of any of these period 4-6 essential heavy metals may increase susceptibility to poisoning by toxic heavy metals. (emphasize essential and toxic, but maybe with only two or three apostrophes instead of the five I've used.)
 * This is good but we can't go that far. For example, if I have an iron deficiency I don't know what impact that would have on my toxic intake threshold for an essential heavy metal like selenium. I did however change the reference to period 4--6 "elements" to "heavy metals".
 * What about if we said "A deficiency of any of these period 4-6 essential heavy metals may increase susceptibility to poisoning by one or more toxic heavy metals."? YBG (talk) 04:52, 8 August 2016 (UTC)
 * Still won't work, I think, because Se, for example, is an essential heavy metal, not necessarily a toxic heavy metal. Hence referring to an increased susceptibility to HM poisoning works better because it's a neutral term. Sandbh (talk) 10:48, 8 August 2016 (UTC)
 * OK, I think I see it now. The HM poisoning may be from a little bit of a toxic HM or way too much of an essential HM. YBG (talk) 23:47, 8 August 2016 (UTC)
 * "Titanium (...)" Change to "Titanium (not always considered a heavy metal)"
 * Done; that was a good'un. Sandbh (talk) 02:29, 8 August 2016 (UTC)

Formation &c
✅
 * "up to the vicinity of iron" I presume "vicinity" means atomic number, if so, maybe make it more obvious by stating "up to about atomic number 26 (iron)".
 * Yes, that's it. I added something about this towards the end of the para.
 * Why not just say "up to the iron peak? I it is better without pipe-hiding the wikilink -- and "iron peak" includes the idea of "vicinity"?
 * Also, what about changing "... resulting in the formation of heavier elements (i.e. those with higher atomic numbers) and the release of light and heat." to "... releasing light and heat and forming heavier elements with higher atomic numbers."
 * Superb! Done. Sandbh (talk) 09:19, 8 August 2016 (UTC)
 * YBG (talk) 05:13, 8 August 2016 (UTC)
 * "are largely made by way of ..." Maybe "largely arise from" or "are largely made by ..."? "by way of" is overly verbose.
 * Agree, and changed to "via".
 * "In this process" drop this phrase and connect to previous sentence with a colon, so "nucleosynthesis: lighter elements from hydrogen to silicon undergo successive fusion reactions inside stars, forming heavier elements and releasing light and heat"
 * I'm inclined not to do this it would result in an unusually long sentence, and a 1-paragraph one at that although I'm less worried about 1-sentence paras.
 * What does the "r" in "r-process" stand for?
 * Done.
 * Paragraph 2 seems longish -- can it be broken up?
 * I think this one is OK. It is long, but it's self-contained, and an occasional longer paragraph serves to refocus the mind (at least it does for me).
 * Paragraph 3: "subsequently" sounds like it means afterwards, as in after the previous clause which says "late in theri stellar lifetimes" Maybe "Stars lose much of their mass by ejection, either late in their stellar lifetimes or following a neutron star merger, in either case, increasing the abundance of heavier-than-helium elements in the interstellar medium.
 * Yes, the "subsequently" does mean afterwards i.e. after the star has lost much its mass and all that's left is a neutron star…then along comes another neutron star… I've changed the words to make my meaning clearer.
 * Move "Late in their lifetimes" to the beginning of the sentence so it is clear that that subsequently/thereafter refers back to the ejection event, not to late in their lifetimes. YBG (talk) 04:29, 8 August 2016 (UTC)
 * Will look again at this one.
 * Is that clearer? Sandbh (talk) 10:42, 8 August 2016 (UTC)
 * Now I'm left wondering how a merger causes a loss of mass. YBG (talk) 23:44, 8 August 2016 (UTC)
 * Well, that is what the open access source explains. I'll look at this again and see if I should add anything---I guess it us a question of how much detail one goes inot. Sandbh (talk) 01:34, 9 August 2016 (UTC)
 * I added a note about this. Sandbh (talk) 03:05, 9 August 2016 (UTC)

Hope this is helpful. YBG (talk) 06:11, 7 August 2016 (UTC)
 * Paragraph 4: Change end to "as a result of mountain building, erosion, or other geological processes" and maybe add some wikilinks.
 * Good, done.
 * Paragraph 5: "are nearly all represented by the" Not sure what "represented" means here. Do you mean "are mostly the f-block elements and the more reactive ..." or "are most of the f-block elements and the more reactive"?
 * I took out "represented". I hope it reads better now.
 * It is a bit discordant to say more reactive d-block elements but less reactive transition metals. What about "Lithophile HM are mainly f-block elements and the more reactive of the d-block elements. .... Chalcophile HMs are mainly the less reactive d-block (transition) metals and s-block (post-transition) metals." Not sure whether wikilink the (T) and (PT) or delete the (T) and (PT) completely. YBG (talk) 05:02, 8 August 2016 (UTC)
 * Yes, good! Done. Keep the T and the PT; they're wikilinked earlier on. Sandbh (talk) 09:15, 8 August 2016 (UTC)
 * This leaves the discord. The reader sees you've mentioned the "more reactive d-block elements" and the "less reactive transition metals" and wonders, what about the less reactive d-block elements and the more reactive transition metals? YBG (talk) 23:44, 8 August 2016 (UTC)
 * This should be fixed now. Sandbh (talk) 03:26, 9 August 2016 (UTC)
 * Yes, muchly! Sandbh (talk) 03:43, 8 August 2016 (UTC)
 * I felt bad that I'd spent so much time with the minutiae of those two tables that I hadn't dome much review of these other sections until the 2nd nomination came up. YBG (talk) 04:34, 8 August 2016 (UTC)
 * I've appreciated all of your valuable help; no need for you to feel bad on my part. Sandbh (talk) 04:40, 8 August 2016 (UTC)

Now that this article has been renamed, what should its title really be?
2016-08-07 Sandbh nominated Heavy metal (chemical element) (this article) at WP:Featured article candidates#.... Something like a discussion about moving (renaming) this article took place over there, and then Sandbh moved this article to Heavy metal (science and technology). (WP:FAC is the place for nominating, but work was needed. Nomination looked premature. It says there "Before nominating an article, nominators may wish to receive feedback by listing it at peer review." (I.e., fix up an article and then nominate it.)) The discussion at FAC was mentioned at the top of this talk page, and Sandbh mentioned it again in the edit summary of the move. Before the move(s), nothing mentioned that the discussion (over at FAC) was also "discussing" moving (renaming) this article. (I couldn't care less about any "Featured Article" discussion or decision, so I would never follow such a link. I'm only on this talk page to question the move.)

I have a funny feeling about this move. Maybe it was better left undone. It is not a casual decision.

First of all: Heavy metal (chemical element) only needed the suffix "(chemical element)" because Heavy metal is a disambiguation page. (None of the multiple uses of "heavy metal" was deemed "primary".)

One impetus for moving from "Heavy metal (chemical element)" is that "metal" also refers to every alloy, and alloys are mixtures, not elements.

One could argue for Heavy metal (chemistry) because "heavy metal" is a chemical term that refers to the atoms, whether in solid metals, solid salts, or aqueous solutions; whether pure, alloyed or mixed. Heavy metal (chemistry) (created 2015-05-09T20:43:11‎ by Sandbh) is (currently) a redirect to Toxic heavy metal. (It probably should redirect to THIS article, but only after checking what links to it.) This is a potential gridlock. Consider making "Heavy metal (chemistry)" the article about the elements, while leaving "Toxic heavy metal" as the article about the toxic elements. Toxic heavy metals are obviously a subset (at least until some bureaucrat mis-deems beryllium a toxic heavy metal). (Related articles include Metal toxicity.)

One could also argue for Heavy metal (physics). Physics defines what "heavy" means (mass and atomic mass), and most definitions for "metal" are owned by physics (mechanical properties, electrical properties). But the physics term excludes chemical aspects. Chemistry, actually a subset of physics, branched off because of its depth and complexity. Most chemists inevitably use physical measurements every day, while many physicists never use chemistry, ever. The elements belong to chemistry (except when they decay). Reactive ions belong to chemistry (except when they are accelerated).

Copied from the intro of Metallurgy: "Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, ..." (follow those links)

Thus I think chemistry owns "heavy metal", especially as used here, more than do physics, engineering, or technology. I wouldn't say science owns that definition because it is too general (besides physics, science includes math, biology, psychology). So science and technology is way too general to own it.

Here are the renaming edit summaries:

The latest rename to Heavy metal (science and technology):

 06:12, 18 August 2016‎ Sandbh ... (Sandbh moved page Heavy metal (chemical elements) to Heavy metal (science and technology): Discussion at WP:FAC---dissatisfaction with HM (chemical element) and HM (chemical elements)---this one seems to be more encompassing)

A prior (minor, short-lived) rename to Heavy metal (chemical elements):

 23:35, 11 August 2016‎ Sandbh ... (Sandbh moved page Heavy metal (chemical element) to Heavy metal (chemical elements): Change from HM (chemical element) to HM (chemical elements) to avoid giving impression that there is a chemical element called "heavy metal" in the same manner...)

In closing, -A876 (talk) 19:24, 7 September 2016 (UTC)


 * I don't really like the current title as it is a bit long in its disambiguation, as well as the above concern. Perhaps Heavy metal element, Heavy metal (element), Heavy metal (metallurgy), or even Heavy metal (metal) would be more succinct. I could live with Heavy metal (chemistry). Graeme Bartlett (talk) 05:51, 8 September 2016 (UTC)

An argument for Heavy metal (science and technology) would be: It is shorter than Heavy metal (chemistry, biology, and metallurgy) (which tells which sciences and technology apply). (But it's silly long.)

I'm almost definitely wanting THIS PAGE to be the primary Heavy metal article. I've just added a hatnote here to disambiguation page. If someone says "heavy metal", I (and I presume most people) assume that they refer to the metal(s) or element(s) (solid or ions or compounds), except if they are talking about listening to it, playing it, reading it, or watching it. The music, magazine, films, videos, etc. only have secondary claims to the phrase, because they have borrowed it, because it sounds cool. A heavy metal bullet is heavy metal. Heavy metal music is data. -A876 (talk) 17:09, 9 September 2016 (UTC)


 * I like the primary option, and the hatnote. Historical precedent would appear to lend support, as you note. The actual metal sense dates from as early as 1817 whereas the musical sense dates from (AFAIK) no earlier than the 1960s. Sandbh (talk) 23:40, 9 September 2016 (UTC)


 * WP:PRIMARYTOPIC lists two major aspects of being primary topic, usage and long-term significance. The former leans toward HM music and the latter toward HM(S+T):
 * {+music} A topic is primary for a term, with respect to usage, if it is highly likely—much more likely than any other topic, and more likely than all the other topics combined—to be the topic sought when a reader searches for that term.
 * {+(S+T)} A topic is primary for a term, with respect to long-term significance, if it has substantially greater enduring notability and educational value than any other topic associated with that term.
 * WP:PRIMARYTOPIC lists three tools that may help support the determination of primary topic. I believe all measure usage and so would lean toward HM music:
 * {+music} Incoming wikilinks from Special:WhatLinksHere
 * {+music} Wikipedia article traffic statistics
 * {+music} Usage in English reliable sources demonstrated with Google web, news, scholar, or book searches (NOTE: adding  to the Google search string eliminates personal search bias)
 * WP:PRIMARYTOPIC lists four proposed criteria that have never won general acceptance, and gives counterexamples for each. Of these, three would seem to be relevant in this case, and in all three, the general principal would lean toward HM(S+T) but the counterexample is more similar to HM music:
 * {+(S+T) general principal} Historical age
 * {~music counderexample} (Kennewick, Washington is primary for Kennewick over the much older Kennewick Man)
 * {+(S+T) general principal} If a topic was the original
 * {~music counderexample} (Boston is about Boston, Massachusetts, not the English city that first bore that name)
 * {N/A general principal} Principal relevance only to certain people groups
 * {N/A counterexample} (House of Lords is about the UK's House of Lords, even though there have been many other Houses of Lords)
 * {+(S+T) general principal} If a topic has only ascended to widespread notability and prominence recently
 * {~music counderexample} (ISIS does not take the reader to an article on an Egyptian goddess)
 * I see some other ideas here that I do not find mentioned in the general DAB discussions (using the terms from WP:NCDAB):
 * HM music has a natural disambiguator, and so, even if it were the primary topic, I don't think the page would not be Heavy metal.
 * HM (S+T) has no natural disambiguator, and from the discussion above, no parenthetical disambiguator that easily wins wide acceptance.
 * I'm not sure what to make of these observations, but I offer them here for you consideration. IMHO, if we can decide on a parenthetical disambiguator, it shouldn't require discussion beyond this talk page. But deciding to not use a disambiguator would probably require a discussion involving other editors, e.g., those who are interested in music but not in groups of chemical elements. YBG (talk) 13:19, 12 September 2016 (UTC)
 * I read the policy around primaries last night and saw that historical first use doesn't count for much and that popularity, as a search term, does. The musical genre would be much more popular than the metallic substance concept. So the case for making heavy metal the primary appears quite weak. I like Graeme's suggestion of Heavy metal (metal). The one weakness it has is that it could construed to imply that the article is about a singe metal called "heavy metal". I think this is a remote possibility that is not worth worrying about. Sandbh (talk) 03:44, 13 September 2016 (UTC)
 * Heavy metal (metals) would avoid the idea that it is one metal, we might get away with Heavy metals too (currently a redirect to Toxic heavy metal), but I suspect both fall afoul of the naming standards. Graeme Bartlett (talk) 12:15, 13 September 2016 (UTC)
 * I do like Heavy metals. Or Heavy metal metal, since there is no plural for metals equivalent to the "music" in Heavy metal music. Perhaps better would be Heavy metal (periodic table). I see WP:TITLE allows for plurals to cater for "names of classes of objects (e.g. Arabic numerals or Bantu languages)", so Heavy metals would be OK. At the moment I'm torn between these three options. Sandbh (talk) 21:33, 13 September 2016 (UTC)
 * I'm switching my preference to Heavy metal (metals). It doesn't have a plural in the main part of the title; it's less awkward than Heavy metal metal; it accommodates elements and their alloys; it doesn't imply there is a single metal called "heavy metal"; and it captures the subject matter precisely. Sandbh (talk) 03:29, 14 September 2016 (UTC)
 * If in fact plurals are allowed in article titles, then I would strongly favor Heavy metals over any of the others that have been listed. I find any of the things with metal repeated to be very clumsy. YBG (talk) 04:54, 14 September 2016 (UTC)
 * That would be OK with me. Anybody else? Sandbh (talk) 05:14, 14 September 2016 (UTC)
 * Out of my suggestions, Heavy metals seems to me to be the best, being compact, not waffly, not excluding some disciplines, and not sounding silly eg Heavy metal (heavy metal). Graeme Bartlett (talk) 05:57, 14 September 2016 (UTC)

Article title has been changed to Heavy metals; you may need to update your watchlist. Sandbh (talk) 13:07, 16 September 2016 (UTC)
 * Okay, done! Double sharp (talk) 14:40, 16 September 2016 (UTC)
 * I did the change via a copy and paste, and adjusted the associated redirect pages, as there was already a Heavy metal article (a redirect to Toxic heavy metal). Of course, I completely overlooked :( the fact that in so doing, the HM (science & technology) history would be left behind; ditto the talk page history. YBG has since asked for admin assistance to merge the orphaned histories into the heavy metals and talk histories. Sandbh (talk) 07:19, 17 September 2016 (UTC)

The List
In, thorium is listed as being neither Common Commodity , Strategic, Precious, nor Minor - despite the fact that Minor is defined as anything that is neither Common Commodity , Strategic, nor Precious. Sounds like an error to me. Anyone know what's right? YBG (talk) 04:06, 13 September 2016 (UTC)
 * Oh! It should be minor since it's neither Common Commodity, Strategic nor Precious. Sandbh (talk) 07:38, 13 September 2016 (UTC)
 * Common→Commodity above YBG (talk) 06:46, 14 September 2016 (UTC)
 * What about using a table formatted like this?
 * {| class="wikitable"

! colspan=2 | Strategic heavy metals (considered vital to the national interests of multiple countries) ! colspan=2 | Minor heavy metals (neither commodity, precious nor strategic metals) ! Commodity heavy metals (traded by the tonne on the LME) ! Precious heavy metals (rare, naturally occurring and costly)
 * + Classification of heavy metals
 * - valign=top
 * Antimony *
 * Cerium
 * Dysprosium
 * Erbium
 * Europium Radioactive.svg
 * Gadolinium
 * Gallium
 * Holmium
 * Indium
 * Lanthanum
 * Lutetium
 * Neodymium
 * Niobium
 * Praseodymium
 * Promethium Radioactive.svg
 * Samarium
 * Tantalum
 * Terbium
 * Thulium
 * Tungsten
 * Uranium Radioactive.svg
 * Ytterbium
 * rowspan=3 |
 * Actinium Radioactive.svg
 * Americium Radioactive.svg
 * Arsenic *
 * Astatine Radioactive.svg†
 * Berkelium Radioactive.svg
 * Bismuth (Radioactive.svg)
 * Bohrium Radioactive.svg
 * Cadmium
 * Californium Radioactive.svg
 * Copernicium Radioactive.svg
 * Curium Radioactive.svg
 * Darmstadtium Radioactive.svg
 * Dubnium Radioactive.svg
 * Einsteinium Radioactive.svg
 * Fermium Radioactive.svg
 * Flerovium Radioactive.svg
 * Hafnium
 * Hassium Radioactive.svg
 * Lawrencium Radioactive.svg
 * Livermorium Radioactive.svg
 * Manganese
 * rowspan=3 |
 * Meitnerium Radioactive.svg
 * Mendelevium Radioactive.svg
 * Mercury
 * Moscovium Radioactive.svg‡
 * Neptunium Radioactive.svg
 * Nihonium Radioactive.svg‡
 * Nobelium Radioactive.svg
 * Plutonium Radioactive.svg
 * Polonium Radioactive.svg
 * Protactinium Radioactive.svg
 * Radium Radioactive.svg
 * Rhenium
 * Roentgenium Radioactive.svg
 * Rutherfordium Radioactive.svg
 * Seaborgium Radioactive.svg
 * Technetium Radioactive.svg
 * Tennessine Radioactive.svg‡
 * Thallium
 * Thorium Radioactive.svg
 * Vanadium
 * Zirconium
 * - valign=top
 * Zirconium
 * - valign=top
 * - valign=top
 * Chromium (also strategic)
 * Cobalt (also strategic)
 * Copper
 * Iron
 * Lead
 * Molybdenum
 * Nickel
 * Tin
 * Zinc
 * Gold
 * Iridium (also strategic)
 * Osmium (also strategic)
 * Palladium (also strategic)
 * Platinum (also strategic)
 * Rhodium (also strategic)
 * Ruthenium (also strategic)
 * Silver
 * }
 * {| style="margin-left:20px; line-height:1.2"
 * }
 * {| style="margin-left:20px; line-height:1.2"


 * - valign=top
 * width="30pt" style="text-align:center"| * || Antimony and arsenic are commonly recognised as metalloids
 * width="30pt" style="text-align:center"| † || Astatine is predicted to be a metal
 * width="30pt" style="text-align:center"| ‡ || Moscovium, nihonium, and tennessine are provisional names
 * width="30pt" style="text-align:center"| Radioactive.svg || Radioactive metals, including naturally occurring metals like uranium and synthetic ones like americium.
 * width="30pt" style="text-align:center"| (Radioactive.svg) || Bismuth is radioactive but effectively stable, with a half-life of 19 billion billion years, over a billion times the 13.8 billion year estimated age of the universe.
 * }
 * width="30pt" style="text-align:center"| Radioactive.svg || Radioactive metals, including naturally occurring metals like uranium and synthetic ones like americium.
 * width="30pt" style="text-align:center"| (Radioactive.svg) || Bismuth is radioactive but effectively stable, with a half-life of 19 billion billion years, over a billion times the 13.8 billion year estimated age of the universe.
 * }
 * }


 * YBG (talk) 06:46, 14 September 2016 (UTC)


 * YBG: I'm agog at your graphics-fu. Please proceed! Sandbh (talk) 09:52, 14 September 2016 (UTC)
 * The table looks OK, but I am a little concerned about its accessibility. Another issue I have is that not all the REE would be strategic.  Some are just about useless. Graeme Bartlett (talk) 21:51, 14 September 2016 (UTC)
 * Well, REE are rated as critical/strategic by the European Commission; the Government of the Russian Federation (Heavy REE only); the UK Government; and Geoscience Australia. See: Chakhmouradian A.R., Smith M. P. & Kynicky J. 2015, "From "strategic" tungsten to "green" neodymium: A century of critical metals at a glance", Ore Geology Reviews, vol. 64, January, pp. 455–458, ---Sandbh (talk) 00:20, 15 September 2016 (UTC)
 * I agree about accessibility. The headers and contents are separated too far from each other and there is no way a screen reader could make the connection. I will work on another version which will not separate the labels from the lists. YBG (talk) 03:56, 15 September 2016 (UTC)

Version 2
As promised:

I don't think it is quite a visually appealing, but I believe it is better in the accessibility department. YBG (talk) 05:39, 15 September 2016 (UTC)
 * This highlights in the correct order, so screen readers should make sense. I would ask for a distinction between the minor elements, that you could buy, and the highly radioactive short lived elements, that have to be manufactured or extracted on demand (artificial/manmade elements). So you would need another table. I would put Promethium in the artificial category by the way! Graeme Bartlett (talk) 11:25, 15 September 2016 (UTC)
 * I don't think it makes sense to say that Eu is radioactive. Granted it has a natural radioisotope, but the half-life is too long to worry about. Additionally, indeed a note for Bi would be a good idea, but I would not put a radiation sign on it. You would have to be some sort of ageless immortal living on an incredibly time scale to need to worry about that.
 * Additionally, I would make a distinction between radioactive metals that you can actually mine (Th, U) and those you can't, either because they are too short-lived (Po, Ra, Ac, Pa) or because they are essentially absent in nature (Tc, Pm, At, Fr, Np onwards.)
 * Finally, I would not use the provisional names Nh, Mc, and Ts until they are actually approved. Our de facto guideline on this (which I remember having been applied for Cn, and then later for Fl and Lv) is not to use them unless the provisional names are the primary subject. So they should still be called Uut, Uup, and Uus until November. Double sharp (talk) 12:46, 15 September 2016 (UTC)

DS attempt
What do you think? Double sharp (talk) 12:53, 15 September 2016 (UTC)
 * Looks good to me. I have yet another issue though.  What happened to barium?  Its name means heavy, so it would be a heavy metal. Thanks for dropping radioactive symbol from bismuth and europium! Graeme Bartlett (talk) 12:58, 15 September 2016 (UTC)
 * Barium might be heavy for an s-block element (only surpassed by radium), but at 3.51 g/cm3 it fails to cross the 5 g/cm3 boundary. You do have a point – I think of barium as a heavy metal anyway, perhaps because its soluble salts like BaCl2 are toxic. (OTOH, I can't see strontium as one.) But given how ill-defined the term "heavy metal" is I suppose a sharp boundary can't hurt.
 * I'm glad you like it. I was undecided for a while what to do with elements like radium, but decided that since it does occur in nature (though only at about 1 ppt of the crust) and can be (or at least has been) mined from natural sources, it could stay with its illustrious parents thorium and uranium. Polonium and actinium are still shorter-lived and rarer and are mostly produced from neutron irradiation of bismuth and radium, but I cannot think of a way to bring them down that does not need a lot of explanation. Double sharp (talk) 13:11, 15 September 2016 (UTC)
 * Barium was given its name due to the density of its oxide (5.72 g/cm3) rather than the metal itself. Sandbh (talk) 21:57, 15 September 2016 (UTC)

YBG #3
Yet another alternative. YBG (talk) 04:01, 16 September 2016 (UTC)
 * I like this one! Double sharp (talk) 04:35, 16 September 2016 (UTC)
 * Me too!! Sandbh (talk) 09:48, 16 September 2016 (UTC)
 * This is more tidy and organised, more in a Wikipedia style. Graeme Bartlett (talk) 12:22, 16 September 2016 (UTC)
 * Agree, and I'll refine this one a bit (graphically speaking). Sandbh (talk) 23:54, 16 September 2016 (UTC)
 * I went ahead and posted the refined version of this table. A big thank you for getting us going down this path. Sandbh (talk) 05:09, 17 September 2016 (UTC)
 * BTW, I note that we exclude Ge and Te on the basis that they are semiconductors. This creates a few problems with the superheavies: Cn is also predicted to be one (link). Additionally, it is not actually known experimentally if Mt, Ds, Rg, 113, 115, Lv, and 117 are metals, and Fricke describes 117 as "semimetallic". Double sharp (talk) 05:12, 17 September 2016 (UTC)
 * P.S. I have great difficulty thinking of the superheavies from Fm onwards as heavy metals, since their chemistry is mostly unexplored (indeed Cn is probably a semiconductor and not a metal) and you cannot viscerally feel their heaviness (nor would you for gaseous Cn and Fl). I would personally have pounced on the "superheavy metals" category of Loveland to exclude 104–117 from the bulk of the article for this reason: I can tolerate ending at Lr to finish the actinides. Double sharp (talk) 05:18, 17 September 2016 (UTC)
 * I might exclude mention of the superheavy metal (SHM) name since Loveland is a weak reference and I'm not sure the SHM label is helpful in the context of the article. The article originally referred to HM as including metalloids since that sometimes happens in the literature. Then I ran into some turbulence accommodating selenium (density 4.81 g/cm3), which is sometimes referred to as a HM, especially in the environmental literature. (If Gmelin had been working with the imperial system he may have chosen 300 lbs/ft3 as his light/heavy metal cutoff in which case Se, density 300.27, would've made the grade, but he chose 5 gm/cm3 = 312.14lbs/ft3.) So I decided to apply a stricter interpretation of what is a metal, and hence exclude the semiconducting metalloids Ge, Se and Te. But I forgot about e.g. Cn and maybe 117. So, I'm inclined to go back to the original approach of saying HM include metalloids that meet the density criterion, and that would accomodate Cn and 117, and the rest. The fact that we don't know the chemical properties of e.g. Mt, Ds and Uut I don't think matters, since no one is expecting them to be nonmetals (are they?). For predictions of gaseous Cn and Fl I would add carefully worded note saying this could call into question their status as "heavy/weighty" metals, although they would still presumably be the heaviest known gases. This reminds about historical arguments over whether mercury could be regarded as a true metal in light of its liquid form. Then someone poured some Hg into very cold ice, it froze into a malleable form, and mercury was admitted to the true metal club: see here. Oh, and I don't think the fact that you couldn't viscerally feel the heaviness of the superheavies matters. Same thing presumably applies to e.g. Tc and Po. Sandbh (talk) 01:05, 18 September 2016 (UTC)
 * Yes, I think the original approach (including Ge, Se, Te, Cn, and 117) is the best, to be perfectly consistent with the density criterion (and rounding up a little for Se, because it is mentioned too often). Yes, no one thinks Mt–Rg or 113–Lv will be anything other than metals for now. Yakushev et al. said "Fl is the least reactive element in the group, but still a metal" – so we have some precedent for calling copernicium and flerovium true metals in light of their likely gaseous forms. No I can't viscerally feel Tc and Po either (Th and U is the furthest I could go towards instability) – but at least I could imagine doing so with glove-box shielding. I think it's just because no one has ever made quantities of Fm–118 that you can see and that I would let go of that as soon as you could. Double sharp (talk) 04:21, 18 September 2016 (UTC)
 * 1. Good. 2. Perhaps—unless I've missed something—you're attaching too much weight to the need to be able to handle/see these metals (never mind how dense they are) before accepting them as heavy metals? They certainly are heavy in terms of at least atomic number and atomic weight? No one has yet seen At. You wouldn't be able to handle it either---only whatever it was supported by. How does this line of argument sound? Or should we be bust out the super-heavies into their own Transfermium(?) significance grouping? Sandbh (talk) 12:53, 18 September 2016 (UTC)
 * Well, yes, I suppose they are heavy in those terms. I don't think any atomic number division among the artificial elements will really work, because the fugitive astatine (85) comes way before the respectable, long-lived neptunium (93), plutonium (94), and curium (96), even if it does come after technetium (43). So I think the current scheme is the best – or rather it will be after Ge, Se, and Te are reinstated. Double sharp (talk) 13:22, 18 September 2016 (UTC)
 * Ge, Se and Te are back in, and I hived off the artificial elements with half-lives of less than 1 day into their own significance grouping. How does that look? Sandbh (talk) 03:47, 19 September 2016 (UTC)
 * I like it: it's a nice, sharp, arbitrary cutoff. Double sharp (talk) 14:02, 19 September 2016 (UTC)

YBG #4
And another one YBG (talk) 05:49, 16 September 2016 (UTC)
 * With the change to a header of "primoidal" some of those minor elements are now in the wrong box, as polonium, radium, actinium, and protactinium are not primoidal. Also is plutonium strategic for any nations? Graeme Bartlett (talk) 12:20, 16 September 2016 (UTC)
 * I've changed it above to "natural", so that Po, Ra, Ac, and Pa are now in the correct box. Double sharp (talk) 14:24, 16 September 2016 (UTC)
 * None of the government agencies/nations cited in the Chakhmouradian article, including the US DoD and Dept of Energy, list Pu as a strategic. Sandbh (talk) 23:31, 16 September 2016 (UTC)
 * I don't like this version—too busy. Sandbh (talk) 04:45, 17 September 2016 (UTC)

Further discussion
I'd like to advocate for including the micro PT's in the chart. I think it is useful to show how some groups cluster in the PT. YBG (talk) 05:28, 17 September 2016 (UTC)
 * I find it OK for one or two, but having it for every cluster feels like cluttering. Of course, this may be because I (and almost certainly Sandbh) have the whole thing memorised anyway. Double sharp (talk) 05:58, 17 September 2016 (UTC)
 * Agree. Sandbh (talk) 06:03, 17 September 2016 (UTC)
 * Well, I do find it helpful, and that's probably because I don't have it memorized. But adding it to the article in the way I did recently does have the additional advantage of improving (IMHO) the way the labels and definitions of each category appear, mostly due to the smaller font size. But I suppose my addition of the micro PT with all of the HMs may have been too much and so it was reverted. I agree that it mostly duplicates the "heat" chart above. But I did find it helpful to see it in the same scale and presentation as the other micro PTs. But having seen it once, I can do without. What would you think about adding it back in as a collapsible table? I won't do it myself, but if anyone else thinks that might be a way of including the helpfulness of the summary micro PT without being unnecessarily redundant.
 * On a different note, I think the verbage introducing the different categories of significance could be improved. There doesn't seem to be an immediate connection between the term "significance" at the end of the paragraph (and the category names in the table) on the one hand, and the text that appears earlier in the paragraph. I agree that the "significance" categories are useful, but they don't seem to be connected with the rest of the section. Maybe split the last sentence of the paragraph into a new paragraph and add a bit more verbage? YBG (talk) 06:23, 18 September 2016 (UTC)
 * Done. Sandbh (talk) 12:36, 18 September 2016 (UTC)
 * But what exactly is "significance" in this context? YBG (talk) 14:59, 18 September 2016 (UTC)
 * Economic or occurrence significance. I hope the latest iteration works. Sandbh (talk) 03:48, 19 September 2016 (UTC)
 * Yes, that was helpful. I've tweaked it some more, but I'm not completely satisfied. YBG (talk) 04:38, 19 September 2016 (UTC)
 * Ditto. I'm not happy yet. A tough nut to crack. Sandbh (talk) 10:34, 19 September 2016 (UTC)
 * Nearly there now. The layout is done. Have to nail down that title; add a note that some artificially produced HM occur naturally but are too rare to economically extract (so will have to undo some of Double sharp's edits); the footnote markers need to be rationalised; the table is marginally too wide for my ipad; and I'm not sure the naturally extracted and artificially produced titles need to be in bold. Sandbh (talk) 01:17, 20 September 2016 (UTC)
 * Well, OK, I can understand taking Po and Ac out (usually made from neutron irradiation of Bi and Ra), but Ra tends to be extracted (there's no other way to make the longest-lived 226Ra isotope) and most of what we know about Pa comes from one single extraction in 1960 from natural sources IIRC. Double sharp (talk) 01:39, 20 September 2016 (UTC)
 * Emsley says that, as well as cyclotron production, it's become viable since 2000 to extract Ac from unwanted thorium fuel pellets that were going to be used in a nuclear reactor in the 1960s. The pellets have 3% U-233 and this has been decaying via Th-229 to give Ac-225. On Ra, he says it used to be extracted from U ores but is now extracted from spent nuclear fuel rods. Subject to your thoughts I'm inclined to count both of these as forms of (indirect) artificial synthesis, rather than natural extraction (from ores). And I'll move Po. Sandbh (talk) 08:29, 20 September 2016 (UTC)
 * I'm a little outdated here evidently then, since as you know I'm only familiar with the rare radioactives (i.e. anything but Th and U) through summaries in texts. So yes, I think this would mean that Po (neutron irradiation of Bi), Ra (from spent nuclear fuel), and Ac (from unwanted Th pellets) should now be in the artifical category, based on how they are commonly made. What about Pa? Do we make that from neutron irradiation of 230Th now? If so it should join the others. Double sharp (talk) 08:50, 20 September 2016 (UTC)
 * I haven't found anything yet to say that Pa is now made artificially rather than being sourced from the 1960s UK stash refined from uranium ore. So, I'll leave Pa as a minor until something turns up to the contrary. Sandbh (talk) 01:27, 21 September 2016 (UTC)

Latest iteration of the table
Oh wow! That's stunningly pretty. I love the reduction in table line clutter. Is there a way to get rid of the borders around the micro-PTs? Sandbh (talk) 06:47, 20 September 2016 (UTC)


 * I've made a bunch of formatting changes and overall I'm pleased with the result.
 * Overall width reduced by nearly 6%, hopefully enough for S&bh's ipad. (YBG)  -- Sandbh (talk) 08:37, 20 September 2016 (UTC)
 * Cleaner now that vertical lines are eliminated and also the border around micro PTs (per S&bh above). Maybe I didn't have to do both, but either could be added back in.
 * Background color, double-top-border and bold makes the extracted/synthesized headers stand out
 * Footnotes now are narrower than the table and so have been included within the table itself.
 * I've changed "Artificially produced" to "Artificially synthesized" (is that the correct en-au?)
 * "Artificially synthesized" struck me as a tautological, hence I had "artificially produced". "Synthesized" is acceptable in Oz English. Sandbh (talk) 10:36, 20 September 2016 (UTC)
 * What about making the rows "Extracted from " and "Synthesized " YBG (talk) 04:29, 21 September 2016 (UTC)
 * Hmm, I'd leave it for now unless we can think of something better. I had a quick look in some dictionaries and can't find synthetic associated with being artifical e.g. wool = natural; nylon = synthetic. Might be an Australian thing or I have to look further. Small beer, no rush. Sandbh (talk) 04:52, 21 September 2016 (UTC)
 * I'm generally pleased with the category names
 * Superscripted all footnote markers and used 5-point-asterisk for Bi since it looks a bit like the radioactivity symbol (YBG)
 * Ah, now I follow. I tend to think the section mark in the title is jarring and not worth the (obscure to me) resemblance between a 5-pt asterisk and the radiation symbol. Sandbh (talk) 10:36, 20 September 2016 (UTC)
 * I've changed them again - using ＊ in the header and for Bismuth, a white triangle (U+25EC.svg) whose resemblence is much less obscure. YBG (talk) 04:29, 21 September 2016 (UTC)
 * Better, and interesting. Is there a hollow triangle symbol that looks a bit darker? This one is a bit washed out, even when it's bolded. Sandbh (talk) 04:56, 21 September 2016 (UTC)
 * A Greek delta: Δ ? Sandbh (talk) 04:59, 21 September 2016 (UTC)
 * Bold has no impact on images. Could use a delta Δ, or U+25B3.svg or U+25B2.svg, but overall I rather like U+25EC.svg with its almost-invisible dot in the center and the washed-out look apropos of Bi's level of radioactivity. Incidentally, these are all images of Unicode geometric shapes, which might be accessible directly (or maybe not). YBG (talk) 05:54, 23 September 2016 (UTC)
 * Leave it as it is. It's growing on me. Sandbh (talk) 07:05, 23 September 2016 (UTC)
 * Things I'd still like to see changed:
 * Table header: Currently says "... by source, usage or stability, and PT location". I'd prefer "... by source, usage, stability, and PT location" because then "stability" neatly covers two different things: the subclassification of the extracted HM and also the marking of radioactive HM. (YBG)
 * I had used "usage or stability" since the six HM categories spoke to either usage (the first four) or stability (the last two). When I see "usage, stability" I expect to see something about usage and stability, for each of the six categories. But I don't get that. I sure get usage for the first four, and stability for the last two and perhaps (in a deductive way) for the first four, but I don't get usage for the last two. And I never intended for these six categories of convenience to be anything other than a quick and dirty-ish way to get your head around so many HM. Sandbh (talk) 10:36, 20 September 2016 (UTC)
 * What about "by source, usability, stability, and PT location".
 * Usability applies to "extracted" elements because they are subdivided into strategic, commodity, precious, and minor.
 * Usability applies to "synthesized" elements because they are subdivided into long-lived and ephemeral and long-lived elements have a potential for usability that ephemeral ones do not.
 * Stability applies to "synthesized" elements because, although all are marked "radioactive", they are subdivided into long-lived and ephemeral.
 * Stability applies to "extracted" elements because, although the subcategories are oriented toward usability, they are marked as being radioactive or not.
 * I will grant you that usability and stability are not wikt:orthogonal (sense 5, independent and irrelevant to each other), but IMHO, this is relatively minor compared to the glaring clumsiness of saying "w, x or y, and z" where "x or y" is parallel to "w" and "z". YBG (talk) 06:07, 24 September 2016 (UTC)
 * This is clever. Could we revert back to "by source, significance, and PT location"? For a Q&D categorisation scheme, that says all that needs to be said doesn't it? Sandbh (talk) 06:38, 24 September 2016 (UTC)
 * My original problem with "significance" was that it begged the question "significant in what way?" We could probably omit the reference to PT location. What about "by source, usability, and stability"? Also, should the table itself mention that this is density-based? Or maybe the section title is adequate. YBG (talk) 06:59, 24 September 2016 (UTC)
 * I could even live with "by source, economic value, and stability". YBG (talk) 07:31, 24 September 2016 (UTC)
 * My intended answer to the question "significant in what way?" has always been "in the manner shown by the applicable category name". Thus the significance of tungsten is that it's a strategic HM, gold is precious HM, astaine is ephemeral etc. There is no deeper meaning or rationale underlying the significance categories apart from breaking down the large number of HM into smaller groupings that a reader could more easily grasp. Viewed from this perspective I don't think any further qualifier is needed in the table caption. If needs be the footnote could be amended to make it clearer that the significance categories are purely categories of convenience rather than being taxonomically robust. Sandbh (talk) 00:22, 25 September 2016 (UTC)
 * OK, so it answers the question "what makes this element noteworthy?"
 * With that in mind, maybe it would be better not to specify anything in the table header. How about something like this:
 * Table header: Heavy metals (density > 5 g/cm3, informally categorized)
 * Group header: Produced primarily by commercial mining (classified by economic significance)
 * Group header: Produced primarily by nuclear synthesis (classified by stability)
 * YBG (talk) 01:59, 25 September 2016 (UTC)
 * That's good. For the table header, the "informally categorized" bit isn't necessary (in my experience of professional publishing). The density by-line is fine except we might(?) need another footnote explaining the inclusion of Se. For "produced" try "mainly"---there are currently too many p's. Rest is fine. Sandbh (talk) 03:44, 25 September 2016 (UTC)
 * I've removed the "mainly" qualifier as I don't believe it's required. And I changed "nuclear synthesis" to "artificial" transmutation" plus a link to nuclear transmutation. Sandbh (talk) 05:54, 26 September 2016 (UTC)
 * Seems to me that without "mainly" there would be some elements that should be listed in both sections. Are there any of the elements in the top (commercially mined) section that have one or more isotopes that have been produced by nuclear means? If so, without "mainly" in the bottom section, they would need to be listed there also. I suppose some of the "¶" elements might have been isolated from natural ores, but the "commercial" adjective probably means they wouldn't need to be listed in the top section. But overall I think it would be better IMHO to include "mainly" in both sections.
 * By the way, I like the change in the lower section label - especially the addition of the wikilink. And using a smaller font for the (informally ...) comment was a good call, though I would have kept that part in italics. YBG (talk) 06:40, 27 September 2016 (UTC)
 * Yes, without "mainly" you run into problems. For some time, Po, Ra, and Ac were isolated from natural sources, but nobody does that now. There are many medically significant artificial radioisotopes of the natural elements, as well: for example, 99Mo, 213Bi, 51Cr, 57Co, 60Co, 64Cu, 165Dy, 169Er, 67Ga, 166Ho, 111In, 192Ir, 59Fe, 177Lu, 103Pd, 186Re, 188Re, 153Sm, 75Se, 201Tl, and 169Yb. Double sharp (talk) 12:01, 27 September 2016 (UTC)
 * Strategic PT: I'd like the definition part of the caption (the part above the &lt;hr&gt;) to be a single line, but I can't figure out a way to do it. Every other PT caption/definition fits on a single line, it would be nice if this one did too, especially as it already has those two extra lines below the &lt;hr&gt; to explain the overlap between strategic and the other categories. "Vital to multiple nations' interests" works, but I'm not sure it says everything that needs to be said. And when I tested it out, I realized that the size of the list meant that there was a gap below the PT caption, so maybe I'm not as interested in this as I once was. (YBG)
 * Changed to "Vital to multiple nations' strategic interests". Now fits on one line. I may add a comment to the citation entry re which nations etc. Sandbh (talk) 10:36, 20 September 2016 (UTC)
 * Well, it does fit on one line on my desktop but not on my ipad. So I may change it back to the two-line version. Sandbh (talk) 23:37, 20 September 2016 (UTC)
 * Go ahead. The empty space below the PT is uglier than I thought. YBG (talk) 04:29, 21 September 2016 (UTC)
 * Done. Sandbh (talk) 04:52, 21 September 2016 (UTC)
 * Left to my own devices, I'd add "heavy metals" to the PT headers or the extracted/synthesized headers or to both. In "Commodity HM", "commodity" is clearly an adjective and clearly parallel to strategic, precious and minor. But without the HM, "commodity" seems more like a noun and so not parallel to the others. But I can see how leaving out the "HM" gives an overall cleaner look to the table. But I really want to have my cake and eat it too. (YBG)
 * I think I read somewhere about avoiding redundancy in tables and titles, hence I strived to avoid adding HM again, when it's already clear from the table title. Sandbh (talk) 10:36, 20 September 2016 (UTC)
 * Overall, even before these last changes, the table is so much better than where we started and astoundingly better than my first effort above that set S&bh "agog". That design was very, very brittle: imagine how messed up it would have gotten when moving HMs between categories as has been done several times!
 * YBG (talk) 06:59, 20 September 2016 (UTC)
 * Here are some other potential changes.
 * Changing from bulleted lists to unbulleted. I think this would look really great if the lists were also centered, but I can't figure out how to do this. But unbulleted lists is easy -- and would make the whole thing even narrower, all the better for ipods.
 * That would be worth trying but doesn't like it would be easy to do. Sandbh (talk) 23:49, 21 September 2016 (UTC)
 * I can remove the bullets by putting {{tl}plainlist}} immediately after each div col, but I haven't been able to get it centered. YBG (talk) 06:27, 22 September 2016 (UTC)
 * Perhaps ask at WP:Teahouse? Sandbh (talk) 10:02, 22 September 2016 (UTC)
 * Figured it out without WP:TH. What do you think? YBG (talk) 03:50, 23 September 2016 (UTC)
 * Cool. I changed to left align as centred looked weird. Sandbh (talk) 07:05, 23 September 2016 (UTC)
 * Restore some borders. Try each of the following and let me know if they have any merit.
 * Restore borders around micro PTs by removing "border:0px;" from periodic table (micro)
 * No merit. Sandbh (talk) 23:49, 21 September 2016 (UTC)
 * Restore borders & shading in table by adding "class=wikitable" to the {| line in the table.
 * I tried this and all it added was more horizontal lines :( Sandbh (talk) 23:49, 21 September 2016 (UTC)
 * Let me do it in article space and then you can revert if you don't like it YBG (talk) 00:36, 22 September 2016 (UTC)
 * I think I like it. Sandbh (talk) 02:05, 22 September 2016 (UTC)
 * (This will also add shading and borders to the footnotes, but they can be removed if desired, just let me know.)
 * YBG (talk) 05:59, 21 September 2016 (UTC)

Do you think we could get rid of the (also strategic) and use a footnote marker instead. That would, I presume, mean we could have four columns in all six cells, rather than the mix we have now. And it could give us an excuse to try a flying hand footnote marker, although maybe a section mark § would be better given the match to S for strategic. And it would tidy up promethium. Sandbh (talk) 07:22, 23 September 2016 (UTC)
 * The standard order for footnotes is *, †, ‡, §, ‖, ¶, ☞. Although we may not need to follow this, given that apart from the first three, the vast majority of our readers will not recognise this convention, and it will not really make a substantial difference to the few who will – save perhaps that of amused recognition. Double sharp (talk) 07:33, 23 September 2016 (UTC)
 * How does it look now, with "Strategic" and "Non-strategic" headers in the columns? My only concern is that in order to make things work out I had to use which may be a bit messy for accessibility and screen readers. YBG (talk) 04:49, 24 September 2016 (UTC)
 * It looks good. Screen readers would interpret a non-breaking space as just another space, wouldn't they? Sandbh (talk) 06:54, 24 September 2016 (UTC)
 * The problem isn't the nbsp, but the empty list element. YBG (talk) 07:01, 24 September 2016 (UTC)

Also, why is Pm strategic? Atomic batteries? Double sharp (talk) 08:12, 23 September 2016 (UTC)
 * It's a REM, and the source notes that REM are counted as critical/strategic. Sandbh (talk) 08:24, 23 September 2016 (UTC)
 * I am not entirely sure if that is what they meant, even if it is what they said, but I suppose we'll have to just follow that. Although I do wonder if they had earlier explicitly restricted this to natural elements. Double sharp (talk) 10:48, 23 September 2016 (UTC)
 * I'll see if I can look that up. Sandbh (talk) 11:22, 23 September 2016 (UTC)
 * Yep, drilled down some more. Pm not strategic. Good call. Sandbh (talk) 12:29, 23 September 2016 (UTC)
 * Great! Without this, I wouldn't have been able to distinguish strategic/non-strategic in the way I did. YBG (talk) 04:49, 24 September 2016 (UTC)

More discussion of the list
Per, should Tc have a ¶? YBG (talk) 21:17, 11 October 2016 (UTC)
 * You're right, it should. Added. Double sharp (talk) 02:30, 16 October 2016 (UTC)

Beryllium and aluminium - mostly ionic?
Be and Al are usually the most common examples in high-school chemistry of not-completely-ionic metals – consider BeCl2 and AlCl3. Double sharp (talk) 03:25, 16 September 2016 (UTC)
 * But they are definitely not heavy metals, call them light metals if you like. Graeme Bartlett (talk) 12:12, 16 September 2016 (UTC)
 * Yes, but I raised this because the class A-class B distinction is given in the fourth paragraph of the "Definitions" section, where the article defines class A as "tend to have low electronegativity and form bonds with large ionic character...groups 1, 2, and 3, Ln and An, Al", and the heavy metals to be everything outside class A. So I am not sure this classification makes Be and Al very happy. BTW, Sc, Y, and the lanthanides and actinides would be considered heavy metals by some, but they are clearly class A (although Sc does have some covalent character – for example, ScCl3 sublimes rather than melts, like AlCl3). Double sharp (talk) 14:36, 16 September 2016 (UTC)
 * Agree, that is why the words in question say "tend to". And some would consider Sc, Y, and the lanthanides and actinides to be HM, yet biochemically they are class A and hence not HM from that point of view. Thus, the definitional space of HM is messy. It would be better to separate notions of "toxic metals" from the categories of light metals and heavy metals since not all heavy metals are especially toxic and not all light metals are harmless. But in real life mentions of heavy metals "automatically" convey—without foundation as Duffus said—notions of toxicity. Sandbh (talk) 23:49, 16 September 2016 (UTC)
 * To be fair, Th and U are also chemically toxic metals, though they are more like pseudo-transition metals. Presumably the other actinides would be too, if not for the fact that their radioactivity should be your first concern instead. So I would accept the natural actinides, as well as Np and Pu, more readily as HM than the natural lanthanides. (The elements from Am onwards are a different kettle of fish, mostly because I don't see a way you can get much of a body burden of them without dying.) Double sharp (talk) 04:01, 17 September 2016 (UTC)
 * I'll see if Be and Al warrant a note as exceptions to the ionic bonding tendency. Sandbh (talk) 07:27, 17 September 2016 (UTC)
 * Done. Sandbh (talk) 12:10, 18 September 2016 (UTC)

Regarding the bismuth triangle
To my mind, it looks very silly to put anything that looks like a radiation sign on bismuth. It is not like thorium or uranium, where you have to take provisions for the radioactivity, but you can still work with them. No, with bismuth you do not even have to care about the radiation at all. That's why I originally (see above) just used a standard footnote marker for it (§), to completely avoid this association. The other point is that if you are going to mark out bismuth as radioactive, then you also logically end up having to mark out all the heavy metals that have natural radioactive isotopes that have a shorter half-life than bismuth. If 209Bi with 1.9×1019 years deserves a footnote, then I think 176Lu with 3.764×1010 years deserves one even more. It does after all make up 2.6% of natural lutetium. Given that I think it is very silly to mark V, Mo, Cd, In, Te, La, Nd, Sm, Eu, Gd, Lu, Hf, W, Re, Os, and Pt as radioactive, I think a better solution might be to simply stop marking Bi in any way.
 * I agree with your reasoning. Sandbh (talk) 12:55, 24 September 2016 (UTC)
 * I rather like the triangle, as its washed-out look is neatly symbolic of the mini-micro radioactivity. If Bi needs a footnote marker, I like this one. If I understand it correctly, Bi has only this one primordial isotope, whereas the others occur naturally as a mixture of both radioactive and non-radioactive isotopes. So in this way Bi is unique. I would be opposed to marking all of them, whether with § or with the washed-out triangle. But I wouldn't mind removing the footnote marker from Bi. Perhaps the general footnote on radioactivity could also say "Elements which naturally occur with both radioactive and non-radioactive isotopes are not marked, nor is bismuth, whose only primordial isotope just barely radioactive, with a half-life of ...." But then the footnote will extend past a word wrap, sigh. I can't have everything. YBG (talk) 20:07, 24 September 2016 (UTC)
 * Oh, it is not that Bi has only one primoridal isotope. Rather, Bi has no stable isotopes. I've just edited the table, removed the Bi triangle, adjusted the radioactive note, and vertically aligned the footnote markers. How does it look now? Foonotes that go over one line are more than acceptable as long as they wrap properly. Sandbh (talk) 03:34, 25 September 2016 (UTC)
 * Your "no stable isotopes" is much clearer than my "only one primortial isotope". Thanks. And yes, it is much better now, though I will miss that triangle. One unfortunate side-effect of the long footnotes is that it forces the table to grow to its maximum width, which makes for an unpleasant gap to the right of the micro PTs. I tried to move the footnotes outside of the table, but that introduces an ugly gap above between the table and the footnotes. I even tried to wrap the whole thing into a larger table, whose first row is a single cell containing the main table and whose second row is a single cell containing the footnote table, but still there was an ugly gap between the main table and the footnotes. I just now thought of another alternative which I will try after saving this post. YBG (talk) 04:28, 25 September 2016 (UTC)
 * Well, I made the change but there's still an unpleasant gap between the main table and the footnotes. YBG (talk) 04:38, 25 September 2016 (UTC)

Also, regarding protactinium: our article says that it is now more often produced by neutron irradiation of thorium. Cotton's Lanthanide and Actinide Chemistry agrees with this. OTOH, The Chemistry of the Actinide and Transactinide Elements still lists the UKAEA production from the "ethereal sludge" as the main source of Pa. So I think we should leave it up there for now. I have not found information about Ra, although this could possibly be because unlike Pa, its chemistry is fairly boring, differing from Ba only quantitatively rather than qualitatively. (I reckon we get the same problem with Ac and La.) Double sharp (talk) 09:08, 24 September 2016 (UTC)
 * Our article's mention of Pa production is unsourced. As I read Cotton, he isn't completely clear on this point (p. 148). He says Pa is not generally extracted and then says most of what we know of its chemistry originates with the 1960 extraction of about 125 grams worth. Ullmann's (2012) refers to the 1960s stash and then says, "In future, larger quantities of 231Pa might be recovered from nuclear waste originating from reprocessing of thorium fuels [italics added]." Sandbh (talk) 12:55, 24 September 2016 (UTC)

re Origin and use of the term
It seems to me that it would be more natural if we stated that up until (when?) all known metals were 'heavy metals', that when the elements now known as 'light metals' were discovered, their 'metallicity' was something of a controversy, that this controversy was finally resolved by calling these newer elements 'light metals' and as a result the longer-known metals came to be known as 'heavy metals'. The wordsmithing needs some work, but this progression seems IMO to be a bit better than what is described in the article. All I can say is, I'm glad they didn't choose to bifurcate metals into 'light metals' and 'other metals'. Yuck! YBG (talk) 20:42, 6 October 2016 (UTC)

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"Heavy metal"
FYI, the meaning and usage of is under discussion, for the move request, see talk:heavy metal music -- 64.229.90.172 (talk) 05:49, 15 June 2023 (UTC)