Talk:Noble gas

Applications

Para 3 begins: "Helium has a low solubility in fluids, leading to its use, along with oxygen, for breathing by deep-sea divers because helium does not dissolve in blood and therefore does not form bubbles upon decompression."

Unfortunately helium does dissolve in blood and other body tissues under the increased ambient pressures experienced by divers. In fact, He dissolves and comes out of solution much faster than nitrogen and can cause bubbles (hence decompression sickness) in the same way. See, for example, [1] and the article Decompression_sickness#Helium.

The actual purpose of using He in divers' breathing gas mixtures is to reduce the effects of narcosis. The narcotic potential of most gases is well-correlated with their lipid solubility while He appears to have no observable narcotic effect. This is outlined in the article on trimix and discussed more fully in nitrogen narcosis - the references there would be good to support a better wording on this page.

As an aside, a small cylinder of argon is sometimes used by divers to inflate their drysuits as it has a much lower thermal conductivity than breathing mixtures - this might be worth a mention in this section.

I know that this article is being considered for GA, so I'm loathe to boldy edit it as a fresh editor. Perhaps someone involved in the GA effort could summarise what I've pointed to and do some corrections? If not, would you be happy for me to change that paragraph? --RexxS (talk) 02:32, 16 June 2008 (UTC)

Go ahead and change it, but please add references and format them according to WP:CITE/ES, preferably with {{cite web}}. Gary King (talk) 03:20, 16 June 2008 (UTC)

 Done Hope it meets your standards; some of the cites are journal with an online summary link. Cheers! --RexxS (talk) 17:39, 16 June 2008 (UTC)

I fixed the references. Gary King (talk) 17:51, 16 June 2008 (UTC)

Thanks for sorting out those refs, I'll remember |publisher in future! One small point, you changed the last sentence in the para I edited to say "because (argon) is suitable as a drysuit inflation gas" - just about any gas is "suitable", but argon has the best thermal-resistance/cost ratio, which is why I wrote "good choice". I guess I meant "best choice". Anyway, have a think, you may decide a stronger phrase than "suitable" is better (or not). Cheers and best of luck for the GA, you've clearly worked hard on it - --RexxS (talk) 01:28, 18 June 2008 (UTC)

I have reworded the sentence to better clarify it. Thanks for pointing that out; the way it was before, though, it seemed a bit colloquial. I think "option" makes more sense, too; once you go through the Featured Article process, then every word will have to hold its own weight. Gary King (talk) 15:44, 18 June 2008 (UTC)

Reference 39

The reference 39 cites "Orion's Arm" (for frequency of gas occurrence in the universe) which is a fictional game centuries in the future. Is this valid?--Almstmnntyrs (talk) 03:57, 16 June 2008 (UTC)

It shouldn't be used as a reference, but please leave it there unless you can find a replacement for it. If not, then I will replace it myself soon. Gary King (talk) 15:12, 16 June 2008 (UTC)

Copyedit

I've been asked to copyedit this page by Itub but I see that it is well advanced and looking quite tidy. I've made some minor changes, some notes or questions about some of these are below out of courtesy to all those that are thrashing away toward GA for this. Revert away if others don't agree!

• "Respective" helps disambiguate the point about mps and bps
• Does "Edelgas" need to be capitalised? I've left it as is for now

My German is a little rusty, but I believe it should stay capitalized. It's a proper noun according to the German language. Gary King (talk) 05:07, 20 June 2008 (UTC)

• "included these noble gases as group 0 in" gets rid of two "in"s close together
• Chemical in chemical compounds is redundant

It depends on the context, since "compound" has several meanings. I think it's used appropriately here. Gary King (talk) 05:07, 20 June 2008 (UTC)

• "It was not until 1962 that Neil Bartlett discovered" requires that instead of when unless there is another statement with that later in the sentence, such as in "It was not until 1962 when Jack discovered beer that he married Jill". Bless the man. Or beer.
• The neon picture's caption reads awkwardly with the two sets of brackets but I don't really have a suggestion

I did have a suggestion for that. Franamax (talk) 03:01, 20 June 2008 (UTC)

Which picture are we talking about? Gary King (talk) 05:07, 20 June 2008 (UTC)

This is the one I was thinking of, first one below Noble_gas#Chemical_properties. I'm a little bummed about not having figured out the table alignment thing first, but now I know where to look to see how to do it in future :) Franamax (talk) 06:12, 20 June 2008 (UTC)

• "Lack of reactivity among the noble gases is caused by a full valence shell, resulting in little tendency to gain or lose electrons." in Compounds seems redundant as it has been covered earlier in the article.

Resolved Gary King (talk) 05:07, 20 June 2008 (UTC)

• The properties table would be nicer with the left column "left justified" but I'm not that tech-savvy yet. Note that abundance is not a physical property- this comment was previously placed (hidden) in the text.

Resolved Gary King (talk) 05:07, 20 June 2008 (UTC)

• I've made a few minor changes to sentences to make them sound more "encylcopaedic"

Best of luck with the GA nomination! Freestyle-69 (talk) 23:34, 19 June 2008 (UTC)

Okay, all done. Please take another look. Thanks! :) Gary King (talk) 05:07, 20 June 2008 (UTC)

Well, some have been busy over the weekend (you do get weekends about the same time as the southern hemisphere don't you? :) One minor point- the neon caption now seems to state that helium doesn't have a full valence shell: Neon, like all noble gases except helium, has a full valence shell, meaning it has eight electrons in the outermost orbital

It may require two sentences to get this caption right, I've given it my sugggestion:

Neon, like all noble gases, has a full valence shell. Noble gases have eight electrons in this outermost shell, except in the case of helium, which has two. —Preceding unsigned comment added by Freestyle-69 (talk • contribs) 22:51, 22 June 2008 (UTC)

Abundances

They need to be there just not under a table called physical properties. I would think that adding a sentence about production and abundances and then having a minitable should do the work. Nergaal (talk) 06:15, 20 June 2008 (UTC)

I've moved it. I will convert it to prose later, because I don't think it has too much information; two sentences can easily contain the information in the table. Gary King (talk) 06:29, 20 June 2008 (UTC)

Fact tag - compounds

I've been looking for sources to verify specifically that "argon, krypton, and xenon can form clathrates with hydroquinone, but helium and neon cannot fit because they are too small." I've found a patent here that describes the preparation and potential use of hydroquine/xenon (#20 on the list on that site) and hydroquine/argon (#21), so I can validate the first part of the statement (show the existence of, and demonstrate the usefulness of the clathrate) for Xe & Ar - but I'm struggling to find a reliable source that specifically says He & Ne are too small to form clathrates with hydroquinone. There's a good discussion of hydroquinone clathrate structures in Encyclopedia of Supramolecular Chemistry By Jerry L. Atwood, Jonathan W. Steed, pp 679-686. It might be possible to deduce from there that He & Ne are too small to form a stable clathrate, but that would be original research, so not much use to the article.

However, reference #19 to the Supramolecular Chemistry article points to research on hydroquine/neon interactions (Hermansson K. Host-guest interactions in an organic crystal ...), so we can demonstrate what the article claims to exist - but that still doesn't give us evidence of what doesn't exist :(

I dunno - can anyone find something more concrete or might it be better to drop the unsourced part of the statement until something is found? --RexxS (talk) 22:20, 22 June 2008 (UTC)

Drop it if it's not essential and we can't source it. Gary King (talk) 03:41, 23 June 2008 (UTC)

It is a good statement. Don't delete it yet, but instead add the 2 refs for the first part.Nergaal (talk) 03:42, 23 June 2008 (UTC)

I spent a few hours on that pesky subject this morning. It's awful hard to prove a negative. I asked for a copy of this earlier today but I think my email didn't go through. I'll ask again, but if anyone here has subscription access, shoot me (or all of us) a copy for a look-through. It is a bit important, since noble gases form very few compounds and when they do, stabilization from Van der Waals bonding can sometimes play a part. Franamax (talk) 04:48, 23 June 2008 (UTC)

I've added a reference to Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.. --Itub (talk) 09:58, 23 June 2008 (UTC)

Good stuff. Now can you think of a better wording? "too small to fit" isn't quite right, unless you also explain the lock-and-key concept. Maybe something more like "too small for Van der Waals bonding to stabilize the noble gas atom within the structure"? Or even better, whatever the textbook says! Franamax (talk) 10:35, 23 June 2008 (UTC)

The textbook says "Probably the most famous of all clathrates are those formed by Ar, Kr and Xe with quinol. [...] Similar clathrates are obtained with numerous other gases of similar size, such as O2, N2, CO, and SO2 but not He or Ne, which are too small or insufficiently polarized to be retained. [...] Noble gas hydrates [...] again are formed by Ar, Kr and Xe but not He or Ne." --Itub (talk) 10:59, 23 June 2008 (UTC)

Well, I was going over to fix "or insufficiently polarized to be retained" which is inapplicable to a) monoatomic and b) filled valence shell atoms. That bit can come out without any fear of OR or synthesis. But at the same time, I see you've added formation of "with water" aka clathrate hydrates, and a quick google for "helium clathrate" shows that hydration bonds are quite feasible. The difference here is that hydroquinone is the "classic" example of a clathrate, it has a fixed cage structure where the cavity size comes into play (and I believe was among the very first noble gas compounds discovered); whereas water of hydration can form a stable clathrate structure in almost any range of cage diameters, because H2O can form extended networks of hydrogen bonds. Anyway, the water (or clathrate hydrate), and the hydroquinone clathrate statements will need to be split up to properly address which noble gases can form which clathrates. I would suggest "too small to be retained within the clathrate structure" for hydroquinone, or some other appropriate modifier after "retained". Franamax (talk) 11:55, 23 June 2008 (UTC)

And to Agesworth's edit while I was slowly typing this out: you've changed a directly referenced statement while not adjusting the reference. If you think that large noble gas atoms are somehow polarized in a clathrate structure, can you provide an additional reference? Franamax (talk) 12:16, 23 June 2008 (UTC)

The book says that the same noble gases (Ar, Kr, Xe) form both types of clathrates. Of course, it could be wrong. I don't understand the objection to the idea that noble gas atoms are polarized when forming part of a clathrate. --Itub (talk) 12:18, 23 June 2008 (UTC)

But wait, I see that I mistyped the quote. The book indeed says "polarizable". --Itub (talk) 12:21, 23 June 2008 (UTC)

You beat my temporary strikeout by seconds (longer now - e/c) on my comment on Agesworth's edit and on polarizability, I need to investigate that some more. The original problem I noted is that the current wording says that helium cannot form a clathrate, whereas a google search shows quite clearly that it can - the "too small" limitation applies only to the hydroquinone structure. And just to think about it - the particular clathrate structure is the cage-type, which surrounds the atom, so in which direction do you propose the noble gas atom is polarized? But I do need to better investigate the text, only one of the either/or's should be true in the particular case. Franamax (talk) 12:33, 23 June 2008 (UTC)

(unindent) It depends on the geometry of the clathrate. Perhaps it will be too symmetric to induce a dipole on the noble gas atom, but it should be able to induce a higher moment such as a quadrupole or octapole. --Itub (talk) 12:51, 23 June 2008 (UTC)

Here is a link for (binary) helium clathrate hydrate [2]. It's of interest in that it does state helium cannot form a water hydrate, it can form a binary hydrate, and it states "too small" and does not mention polarizability. However it is a primary source. If you can give me the page numbers of the text you are working from, I think I can get them sent to me from the library, just so I can have a better grasp of the subject for my own benefit. Franamax (talk) 13:16, 23 June 2008 (UTC)

It is page 893. I can send you a PDF if you give me an email address. Now, this book is from 1997 and doesn't go too deeply into clathrates (it devotes about two paragraphs to the topic), so it would not be surprising if the information is outdated. However, after a quick look at the article you linked to, it seems to me that helium hydrate has not been made yet without adding something else, such as THF, into the mix. Greenwood and Earnshaw don't say that helium clathrates in general do not exist; they just say that the hydroquinone clathrate and the hydrate do not exist (or did not exist to the best of their knowledge as of 1997). --Itub (talk) 13:35, 23 June 2008 (UTC)

Expanding the lead

The lead needs to be expanded. I have already broken it up into three paragraphs, each with a different topic, which I think makes more sense than what it was before. The three paragraphs need some more information added to them so they form a better summary of the entire article. The third paragraph in the lead especially needs to be expanded and include information on how noble gases are obtained, and some applications of noble gases. Gary King (talk) 05:19, 23 June 2008 (UTC)

Unreliable references

I have added {{rs}} (which shows "[unreliable source?]") to references that are unreliable. If more reliable references, such as scientific journals or books, can be found, then please replace them. Thanks. Gary King (talk) 18:25, 23 June 2008 (UTC)

I'm only able to comment on the reliability of the two diving-related sources (Anttila, Matti. Narcotic factors of gases. Tech Diver / Maiken, Eric. Why Argon?).

I'm tempted to agree that the Techdiver website has no reputation for reliability, but the table as presented there is taken from "The Physiology and Medicine of Diving" by Peter Bennett and David Elliott - which is pretty much the Bible for diving medicine (or at least the number 1 starting point). However, AFAIK it's not available for free on the web while the table of relative narcotic potentials immediately illustrates the point about using helium to reduce narcosis. Now, I guess we could replace the Techdiver reference with a ref to Bennet & Elliott - or even have both? What's best?

Eric Maiken's essay is another matter altogether. WP:RS states "Reliable sources are credible published materials with a reliable publication process; their authors are generally regarded as trustworthy or authoritative in relation to the subject at hand." I would agree that a website is scarcely a "reliable publication process", but Eric Maiken has a huge reputation as an authority in diving physics and physiology. His essay was taken from a seminar on "Thermal Protection" at a tech diving conference and I seriously doubt that you'll find a better analysis than his to support the use of argon for drysuit inflation. I'm happy to look for other sources which may appear to have a more scholarly pedigree, but I still think the one you've got is the best there is. Cheers --RexxS (talk) 02:26, 24 June 2008 (UTC)