Talk:Nitrogen/Archive 1

Archive 1

Archive 2

Dinitrogen absent

The nitrogen molecule is not really dealt with in Wikipedia. There are no search results for "dinitrogen" or "nitrogen molecule" or "Molecular nitrogen". And its not even/really dealt with in the "compounds" section.
Dave 2346 (talk) 17:12, 13 September 2009 (UTC)

premalignant

Sure, use that word if you want. Richard Cane 20:56, 19 May 2005 (UTC)

Thanks, Richard. Precancerous sounds amateurish, or maybe it's just me :-) JFW | T@lk 21:59, 19 May 2005 (UTC)

uptation

tis needs to show how nitrogen is used by plants and how it can be returned if deplenished :*) Scout 21 16:01, 4 August 2005 (UTC)

nitrogen really colourless?

Well, if you see this [1] - air is supposedly slightly blue. Nitrogen being the major component of this, I would expect to be slightly blue in hue - or is this due to the water vapor? -- Natalinasmpf 01:00, 24 November 2005 (UTC)

The scientific folklore, as I remember it, claims that it is the oxygen in our atmosphere causing the blue tint. WayneConrad 20:43, 23 December 2005 (UTC)

Oxygen is blue due to the electronic configuration of dioxygen allowing a forbidden transiton to occur (electron spin inversion) which absorbs yellow light.

I heard that it is oxygen that can sometimes make water blueish?--63.231.189.2 (talk) 01:27, 17 February 2008 (UTC)

nitrogen tire inflation comment

The comment regarding tire inflation may be incorrect. According to the entries on Nitrogen and Oxygen, the Atomic Radius, Covalent Radius and Van Der Waals Radius are all larger for Nitrogen than Oxygen.--Osudude 16:56, 24 January 2006 (UTC)

It's definitely wrong; oxygen generally diffuses faster than nitrogen. See for example: http://www.uigi.com/noncryo.html#Membrane http://www.airproducts.com/Products/Equipment/PRISMMembranes/page01.htm

Nitrogen has a lower molar mass than oxygen (from looking at the periodic table), so the reference the Graham's law should be deleted and further explanation of why nitrogen diffuses slower than oxygen should be given.

Molecular diameter difference between oxygen and nitrogen overcomes their mass difference effect on diffusion.: http://www.sumitomoseika.co.jp/english/product/n2psa.html

My recollection is that that as the atomic number is increased, the atomic diameter decreases if the marginal electron in both elements is in the same shell. Nitrogen and oxygen both top out in the 2 p-orbital, so oxygen being the heavier of the two is smaller in diameter. Likewise flourine is even smaller in diameter and diffuse more rapidly through porous surfaces. Argon on the other hand, which is used to fill the tires of some luxury cars, is in the next period of the table, topping out in the 3 p orbitals, and thus has a much larger diameter and mass than any 2nd period element, and thus has an even lower rate of diffusion.Badocter 19:25, 25 June 2006 (UTC)

This is not a position on how nitrogen diffuses through tires vs. oxygen, but there are two problems with the current assertions. First, a proper like to like comparison should be of common air vs. pure nitrogen, not oxygen vs. nitrogen. Nitrogen is 78.08% of Earth's atmosphere, and oxygen is 21%. Tires inflated with anything besides bottled gases are already going to be over three-quarters nitrogen. Second, when comparing free nitrogen to free oxygen, the comparison should be N(2) vs. O(2) rather than N(2) vs O; in this case, is the current statement in error? ("Nitrogen molecules are larger than oxygen molecules and therefore...").

Advertising

I have marked the section as Advertising because its only sources are at [getnitrogen.org]. Get Nitrogen is, in my assessment, full of bullshit. I've read some of their documentation, and it's all marketing speak to push product. For example:

"Practically all tire engineers throughout this century attribute the gradual loss in tire strength to be the result of 'fatigue' when in reality this 'fatigue' is nothing more than a slow inexorable oxidation taking place at the available double bonds of the rubber molecules."

Basically: "Everyone in the scientific community says X, but they're wrong."

Their so-called experiments also avoid giving any numbers or details on how often tires were inflated, how much time and how many miles between inflation, pressure loss after miles etc, temperatures, the like. They give only failure rates, and also mention that so many used and so many new tires were used. They also talk about tread wear on the outside "due to oxidization" and how that doesn't happen with nitrogen filled tires, which have nitrogen on the inside (how does the nitrogen inside protect the tire tread outside from the oxygen in the air?).

Most importantly, a claim is made that favors a marketed product, and that claim is cited via documents put out by the business selling the product. Do not claim things in Wikipedia articles and then cite the person trying to sell you their bullshit. Cite actual, peer-reviewed studies or at least something independent without a money chain from the marketer or GTFO.

Either put a valid citation on that line or expand it into a separate section or article with explanation of the controversy. A section or article would be useful, as nitrogen has benefits: it does not expand as readily with heat, and so is useful in high-temperature applications such as racing and airline tires where constant pressure is critical. Any other claims are bullshit. --John Moser (talk) 17:03, 10 September 2011 (UTC)

Instant frostbite?

There is a statement that liquid nitrogen can produce "instant frostbite" on contact with living tissue. That depends on what you mean by "instant." You can put a finger or even most of a hand into LN2 and semi-casually flip it around and stir it, without damage, as long as you remove it within the contact limit of about 2 seconds. The Leidenfrost effect protects you for that long, and no frostbite of skin damage is seen. It's just a bit cool. If you guage the timing correctly you can shock onlookers who've read articles like this one, but never actually fooled around with LN2 much. I know, you're going to say WP:NOR. But back at you. Got a reference for instant frostbite? And please quantitate "instant."Steve 21:45, 25 June 2006 (UTC)

The stunt is not without an element of risk as the timing is critical, and since it is done with rapid movement, there is significant risk of splashing the LN2 on one's clothes (or worse, someone elses) -- the Liedenfrost effect won't protect you if you are wearing clothes soaked with LN2 for any period of time. For instruction of proper handling of LN2: http://www.2spi.com/catalog/instruments/nitrodew-supp.html . Dermatologists often use cotton swabs dipped in LN2 for treatment of skin conditions since contact does cause frostbite and death of the top few layers of skin cells in the areas treated -- because of the speed of the treatment and low thermal conductivity of the skin, deeper tissue is not adversely impacted. Frostbite risk is documenented in the MSDS sheet for LN2: http://www.safety.vanderbilt.edu/pdf/hcs_msds/NitrogenCryo_G103_06_04.pdf . Instant is an arguably vague term, clarifying with the words " within a few seconds" is all that was needed.Badocter 03:22, 26 June 2006 (UTC)

I didn't deliberately take out the statement-- dunno what happened to it. Was waiting on concensus. Agreed that LN2 on absorbant clothes or shoes is a disaster. In derm, LN2 is applied to skin in a very different way than when a hand or finger is "dunked" in LN2. A cotton swab seems to act in freezing skin much faster than skin freezes when a finger is put into LN2. Must be a surface-area phenom.Steve 03:58, 26 June 2006 (UTC)

I might add also that the special dermatology sprayer delivers an LN2 mist which has a hugely greater surface area and heat transfer capability than a glob of liquid of the same mass, so again it acts like the vastly larger area of LN2 as you'd get on a swab. The mist really does cause instant frostbite while the glob will sizzle and airhockey slide off unprotected skin, like water on a hot tilted grill, causing no harm. So both of us are really right-- it entirely depends on the circumstances. Get LN2 on your skin in a dispersed fashion and you get instant damage. The liquid globs on bare skin without dispersion by spray or swab or clothing, or dunking the skin into straight liquid, is not instant. Steve 13:34, 26 June 2006 (UTC)

My experience with dermatologists is limited to my acne treatment as a teen, and the cotton swab with LN2 was what my dermatologist used, but that was many moons ago and I expect things have advanced since then. Best Regards.Badocter 17:44, 26 June 2006 (UTC)

Liquid Nitrogen on food?

I heard on the show Beyond Tomarrow on the Science Channel, that there's a resturant called Moto in Chicago, IL, that serves French Onion Soup with liquid nitrogen layered on top. I'm wondering, how could they do this safely? It sounds kind of risky. —The preceding unsigned comment was added by Violet yoshi (talk • contribs) .

I can assure you, if handled by trained professionals, French onion soup is absolutely safe. Oh, you mean the nitrogen… Assuming you're not supposed to actually eat it while it's cold and boiling, I'd say it's less risky than your average flambé any time. Femto 13:46, 6 July 2006 (UTC)

I didn't see the show, but I'm thinking that it was probably a joke. 161.16.0.50 21:11, 8 August 2006 (UTC)

No I saw the show. Liquid nitrogen is lighter than water and skates around on the surface of liquid water like an air hockey puck, on its own gas cussion, due to the Leidenfrost effect (this also happens when you pour it on a flat floor-- it takes off in every direction). And on water, these drops do very little but generate fog, like when you put dry ice in water. So long as you wait to eat it until the drops of liquid nitrogen are gone (fog stops forming, sizzle stops), you're fine. No more than a few seconds would be needed. You could get a nasty mouth cryo-burn before then, though, in theory. As for the soup, with small dolips of nitrogen, you can't cool it below freezing this way, until it's ALL frozen. Which obviously doesn't happen. So if it's liquid, and the nitrogen is gone, the remaining soup is above ice temp and drinkable.SBHarris 22:10, 8 August 2006 (UTC)

Wouldn't you jst freeze your tongue off? AR Argon 05:38, 23 August 2007 (UTC)

Actually some people have even put just liquid nitrogen in their mouth and survived :P The quantities have to be small and swallowing is a bad idea. It just feels very cold. As Sbharris pointed out due to the gas cushion, the liquid nitrogen (that is the liquid part) is not in direct contact with warmer bodies. I have played with liquid nitrogen in university and I can say it's generally safe thing to handle. For example pouring it on the hand is safe if it is able to flow away. Not letting it flow away and keeping it for some time in the hand may give you some small frost burns. However sticking your hand into a container with a larger amount of LiN2 will surely freeze it away pretty quickly. Usually people get the frost burns from other objects that have been cooled down by LiN2. Zimdynee (talk) 02:32, 11 March 2008 (UTC)

Nitrogen safety

Is anyone familiar with how gaseous Nitrogen kills? I don't think it works as a simple asphyxiant, i.e. that it supposedly displaces oxygen. I remember hearing from a safety guy that that's not the case; it it were, it would hurt kind of like drowning. But it's supposed to be unnoticable and painless. 161.16.0.50 20:35, 8 August 2006 (UTC)

It IS a simple asphyxiant. Drowning is unpleasant because it's not fun to have liquid in your lungs. Also because CO2 is building up, which doesn't happen when you breathe nitrogen (or any gas asphyxiant). You're low on oxygen, but can still get rid of CO2, so the sensation of needing to breathe doesn't happen. Humans have good CO2 sensors, which makes holding our breath (or being choked) very unpleasant. But we have lousy low-O2 sensors, so breating gas with no oxygen in it, hardly bothers us at all, till we black out.

That's not true of all animals! Rabbits and burrowers have very good hypoxia sensors, so "drowning" in nitrogen is very unpleasant for them. It's quite a different experience from that of humans. The question comes up occassionally in AALAS discussions of acceptable methods of euthanasia for different species of animals. For humans, replacing hydrogen cyanide gas with nitrogen in the gas chamber would be far more humane (and has been proposed, but hasn't been done, mainly for dumb historical and legalistic reasons). But don't test the system on a poor bunny!

By the way, nitrogen isn't capitalized in English. No element is. Just the symbols are. SBHarris 22:04, 8 August 2006 (UTC)

What is said above is almost correct, except it forget the fact that in a nitrogen atmosphere, when the pure nitrogen gets into the lungs, it creates a diffusion gradient which effectively removes oxygen from the blood back into the lungs. When breathing pure nitrogen, with each breath more and more oxygen is lost from the blood stream, so that the partial pressure of oxygen in the blood can become very low, very quickly. Various sources I've read state that a person breathing pure nitrogen has less than 30 seconds of consciousness, and perhaps even less than that. So things can happen quite quickly in a pure nitrogen atmesphere. This would make escape very difficult, and even donning PPE (a supplied air respirator) improbable. John C. Ratliff (talk) 17:00, 22 August 2008 (UTC)

Liquid nitrogen

Would there be any value in splitting off liquid nitrogen as a separate article similar to liquid oxygen? I'm thinking that there are sufficiently many applications of the liquid, compared with the gas. Also, cryogenics using liquid nitrogen can be more thoroughly discussed there. --Rifleman 82 10:41, 17 November 2006 (UTC)

N2 in tires

Does anyone else think the claim that "Nitrogen molecules are larger than oxygen molecules and therefore, all else being equal, larger molecules diffuse through porous substances slower than smaller molecules." is juuust a bit iffy? I mean we're talking like 2 freaking picometers here. Its barely a few percent difference. I suspect that most of the difference seen in N2 and O2 loss from tires results almost entirely from O2's reactivity with the rubber. Do we at least have a source for the molecule size claim?--Deglr6328 11:25, 3 December 2006 (UTC)

Response- more information/ citations added. -Permeability coefficients measured for oxygen, P O2 , are higher than the values for nitrogen, P N2 , in all known rubbers (elastomers), including those typical of tires. The ratio of the permeability coefficients, P O2 divided by P N2 , is between 3 and 4 depending on the particular rubber. This means that oxygen permeates 3 to 4 times faster through rubber than does nitrogen, other conditions being equal; - Although the difference seems miniscule without context, the relative sizes of the molecules effect significantly more retention of N2. The differing losses can in part be explained by the more volatile reactive reletionship between o2 and rubber, but must also be directly tied to the size difference as the oxygen molecules are capable of shrinking and escaping from the rubber confine whereas the nitrogen are not. A tire filled with regular air can lose 1.5 psi in less than a month compared to a tire with nitorgen's expected rate of no more than 1.5 psi per 6 months. — Preceding unsigned comment added by DaisyLafayette (talk • contribs) 19:57, 20 June 2011 (UTC)

Liquid to solid Nitrogen Video

I have removed the link to the video - http://www.youtube.com/watch?v=Ndbzw60fiYU.

Although this is an interesting video - the way it has been videoed is highly dangerous - and may encourage danergous repeat experiments.

Not only is the nitrogen and helium (used to solidify the nitrogen) extremely cold well under -200 degrees (this temperature if exposed to, could cause almost instant destruction of tissue - as almost showed when this investigator froze his thumb off), but there is a risk of asphyxiation if the room is not well ventilated or the liquid helium is knocked over. Also the investigators do not use appropriate BASIC safety gear - like face guard (one splash of liquid helium in the eye and you are blind), only one glove, adequate ventilation to avoid asphyxiation.

We can not on wikipedia link to this video - the screen shot is not a problem - to do so might encourage people that this is the correct way to handle these extremely dangerous chemicals.

Please either leave a comment here or on my talk page! Lethaniol 14:43, 6 December 2006 (UTC)

This is absurd, I am reinstating the video link. Wikipedia is not censored for idiots and anyone with access to liquid helium is going to know how to handle it properly and if they don't well ts that's why we have Darwin awards. The activities shown in the video are absolutely not overly dangerous. The prof did not "freeze his thumb off" and your statement that "one splash of liquid helium in the eye and you are blind" reveals that you have obviously never worked with the stuff and have little to no grasp of the fundamental physics involved with cryogenic liquids. You would not even feel a splash of liquid helium in your eye, the heat of vaporization is absurdly low, the energy contained within a paperclip at room temperature is enough to boil off something like a liter of helium if I remember right. --Deglr6328 17:36, 22 December 2006 (UTC)

I am going to put this up for Request for Comment as it is a serious issue. The fact that the people that made this video do not know how to safely handle these chemicals shows that there are idiots out there and they have access to these materials. You may be right, but I do not want to get into a revert review with this and so we need outside opinions. Thanks Lethaniol 17:51, 22 December 2006 (UTC)

I have made the link into a reference. I guess it needs a bit more text, but I am afraid if that would be according to wp:not (not a manual/safety guard). But without explanation .. then I think the link would indeed be inappropriate. Two comments, I do concur with User:Lethaniol that the video is potentially dangerous, people might want to copy it, but then, the video is on YouTube, so available anyway (question indeed is, do we need to provide a link). User:Deglr6328, no, though you are right that Wikipedia is not censored for idiots, but it has several policies which do censor information, specifically wp:el and wp:not. But then I do not yet see where these do come into play here. I'd like to hear some other opinions on that. --Dirk Beetstra ^{T C} 18:40, 22 December 2006 (UTC)

I would like to make three extra points, and then as the person bringing the RfC let others debate.

1. The issue of linking to YouTube videos is highly controversial, see Wikipedia talk:External links, with no definite answer in sight. I think we should only add a link to videos if they really add something. Now if this was the article on phase transitions, then a video demonstrating one would be a good idea, but why one for Nitrogen phase transitions specifically.
2. Linking to YouTube videos has lots of potential problems with copy violations again see Wikipedia talk:External links.
3. Finally other respectable encyclopaedias would never have such links to amateur videos on such an important article.

Thanks Lethaniol 18:51, 22 December 2006 (UTC)

I am absolutely blown away by the bizzare nature of the arguments here on this topic. Who gives a toss what a "respectable" encyclopedia would do! We're not talking about some moron mixing vinegar and baking soda in a balloon here. The video is a fascinating science demo done by an actual college chemistry professor using materials and showing phase change phenomena which are exceptionally rare to see otherwise. It is the vertiable definition of encyclopedic! --Deglr6328 22:03, 22 December 2006 (UTC)

Agree. Solid nitrogen is a neat picture, and let's leave it. Liquid He is a handling hazard but not as much as you might think, due to very, VERY low heat capacity. It's damn hard to even SEE liquid helium out of tank, because if you run it though regular cryogenic hoses, enough heat is absorbed that all you get is gas at the other end. You need actual vacuum-jacketed (VJ) transfer lines. I don't think I've ever read of any body getting a liquid helium "burn" on their skin, even in these days of filling up great big MRI machine coils. I'll bet you money it's VERY hard to do. If you look up handing proceedures for handing of liquid helium, of course you get the very same boilerplate stuff you get for any cryogenic liquid handing. What do you expect? There's significantly nothing different in the language used for liquid helium. And as I KNOW how these things are written, if it was the case that liquid helium was actually a little safer to spill on the skin than liquid nitrogen (which I'm bet you it is) you wouldn't be reading that in any safety brocures, just for legal reasons. Anyway, the paranoia I see here is unjustified. If you've handled liquid helium (and I have) you can give us your personal experiences. (Mine is that you'd have a hard time getting enough together and keeping it together long enough to hurt yourself with it). You can give us any SPECIAL safety data on thermal dangers of liquid helium, if you can find it (I'll bet you can't) then post that. Otherwise, you're just making hysterical assumptions based on the idea that colder things are more dangerous, which isn't necessarily true.

And while we're at it, the same kind of thinking goes for this auto tire and nitrogen vs. oxygen thing. You might be able to take a guess at how the gases migrate through rubber, but they are so close that the experiment simply needs to be done before anybody pontificates. And since it seems to have been done, then nature and experiment rule over theory. The only question left is whether the difference seen in migration, and in oxidation, is worth paying for. SBHarris 22:36, 22 December 2006 (UTC)

Responses to RfC

• Strongly recommend to remove picture and link to video - apart from the serious safety issue, the video is original research. There are no sources given of how to prepare solid nitrogen.  Andreas  ^(T) 19:02, 22 December 2006 (UTC)

If this picture is original research, then taking a picture of the Eiffel tower is also original research! They just made some solid nitrogen and took a video of it. The fact is that the melting point of nitrogen is higher than the boiling point of helium, and that is perfectly verifiable. The safety measures in the video are a bit questionable (although in my opinion the dangers of liquid nitrogen are often greatly exaggerated), but it's not wikipedia's job to censor its content for safety. The main issue I have with this picture and video is that they apparently were added only because they were "cool", but they don't add much to the article as it is. The text never refers to the pictures and vice versa; the article never mentions solid nitrogen. The same goes for the picture of the liquid nitrogen ice cream. (This could conceivably be fixed by editing the text of the article so that the pictures become relevant and useful.) Itub 20:09, 22 December 2006 (UTC)

I am rather surprised at this view! First of all, I don't see how it is "original research" at all. I didn't make the video number one, and two, there is no "research" involved here. Its just a science demo. It is common knowledge that nitrogen freezes if you lower its temperature enough. I did not add the image "just because it was cool" (ha-ha) but because it is VERY rare to see solid nitrogen ice anywhere. It is NOT something one regularly encounters even if you are familliar with the liquid. I really don't see the need for the text to refer to the image. The entire page is about nitrogen! Its self explanatory with the caption. --Deglr6328 21:51, 22 December 2006 (UTC)

I viewed the video and I don't see much of a problem. Safety rules are safety rules but ... in real life, you can get away with quite a bit. I agree with the above Deglr6328 that if you can access liquid helium, you should know how to handle it safely. Seeing solid nitrogen is actually rather interesting and encyclopedic. It would be perverse if a floating frog were notable and solid nitrogen were not. --Rifleman 82 20:24, 22 December 2006 (UTC)

CLARIFICATION - I think at least one person got the wrong end of the stick - this is not about the PICTURE of the solid nitrogen, but the link to the VIDEO from YouTube. I do not think anyone will have a problem with a picture of nitrogen, only maybe whether it is interesting or not. Lethaniol 22:58, 22 December 2006 (UTC)

Reccomend removing link to video and picture for the following reasons:

1. They're original reasearch
2. Youtube is generallly not used as a source because it's very unreliable
3. Health and safety considerations

--Redlock 02:49, 25 December 2006 (UTC)

• I think the video nicely illustrates some of the properties of liquid nitrogen. One YouTube user even commented wikipedia rediected me here. good vid, useful on the topic im doing for my project. The Wikimedia projects (including Wikipedia) contain all sorts of information that could be dangerous—Wikibooks has explicit instructions for how to manufacture acetone peroxide, the explosive used for the 7/7 bombings. This is tame compared to that. People are going to find this stuff on the internet, with or without Wikipedia. We might as well keep it. Strad 17:21, 27 December 2006 (UTC)

• I would agree that it is an intersting video. Based upon the lack of health and safety shown in the video, I would suggest that this leaves the question of how reliable the rest of the vidoes content is. Adambro 19:36, 1 January 2007 (UTC)

• The video seems to be able to inspire people to use no lab safety (except for the one glove). I agree that some fault goes to the person who attempts it if by attempting it he/she freezes a finger off etc., but some fault would also go to the link to the video (thus to this article) for giving that person a chance to get "inspired" by the video. Slartibartfast1992 02:55, 3 January 2007 (UTC)

Wow what a tough one! On the one hand I whole heartly believe that everyone should be entitled to access information, but on the other hand the fact that this is a you tube video and that it demonstrates a particularly dangerous experiment is troublesome. However to settle the dispute I've discovered that the Anarchist Cookbook is available on wikipedia with a link to where it can be downloaded. Thus, it would seem the precident of allowing access to dangerous materials is acceptable.

So, leaving out the fact that it's dangerous I feel the next issue is that it's hosted on you tube. Since you tube is fairly stable (read, google bought it, it's not going anywhere) I believe the link should stay. Perhaps we could put a disclaimer next to the link stating that it's not done safely and "should not be tried at home"? Something to that effect would get the message across!--Robert Stone, Jr. 03:35, 5 January 2007 (UTC)

The video does NOT contain original research. How many times do we have to go over this? It has been known for a century now what effects liquid helium has on other materials and the freezing point of nitrogen has been known even longer. The demo they are doing is NOT THAT DANGEROUS! Its probably about as dangerous as the preparation of a spaghetti dinner. Spilling boiling water on your skin WILL burn you instantly. Spilling liquid nitrogen on your skin will not burn you for a few seconds because of the leidenfrost effect and the fact that nitrogen has a very low heat capacity. In fact, I am going to take a picture of me pouring liquid nitrogen on my hand and add it to the article just to wig everyone out.--Deglr6328 12:22, 7 January 2007 (UTC)

But do add the disclaimer that this should not be tried any place other than fairly smooth skin. And keep the LN2 as liquid-- no misting or application with, or to, cloth or high surface-area stuff. The Leidenfrost effect works great, but only in the right circumstances. Pour liquid LN2 on your hand-- no damage. Pour it on your sneakered foot or a sock, you've got a problem. Get sprayed with mist, you're burned, etc. SBHarris 16:50, 22 January 2007 (UTC)

It's clearly encyclopedic, and better for the article than for phase transition. Agree with Robert Stone. — Sebastian 06:57, 22 January 2007 (UTC)

Fact tags about nitrogen and oxygen size and diffusion

I disagree with the User:Beetstra's removal of the fact tags I added to the nitrogen article.[2] The first one can't be explained away by the next sentence, especially when the next sentence is also questioned! Let's start with the second fact tag: Beetstra says that it is based on the infoboxes. What in the infoboxes? If you just look at the atomic radius, you are using it out of context, because air does not have atomic N and O, but N2 and O2. The nitrogen molecule has a triple bond, which is considerably shorter than the double bond in the oxygen molecule (110 vs 121 pm, according to the table in chemical bond). Therefore it seems more sensible to say that N2 is smaller, unless a solid reference can prove otherwise (maybe for some reason I cannot fathom, N2 has a larger "effective" diameter, even if the bond length is shorter, but in that case, where is the reference?). Second, the statement that N2 diffuses through rubber slower than O2 needs some solid evidence, regardless of which molecule is larger. I was going to delete the whole paragraph because I suspect it is an urban legend, but I decided to take the gentler approach of adding the fact tags. I'm readding the tags for now. (I don't dispute that sometimes tires are filled with N2, just the explanation.) Itub 20:51, 22 December 2006 (UTC)

I concur, the second fact decides the faith of the first. But as far as I know, there are (at least) two things in play here. Diffusion is dependent on size and weight. The size is bigger (we are looking along the bond now) where bond length is not of a real effect. But OK, a reference for the van der Waals radii of the two molecules would be nice. Secondly, nitrogen is a heavier atom than nitrogen. That makes diffusion slower (the molecule absorbs more energy on impact). I will leave it for now, see how it develops, but I do think the story is correct (it would probably be better to fill the tyre with argon or xenon, anyway). --Dirk Beetstra ^{T C} 21:15, 22 December 2006 (UTC)

Ok, I think I found an interesting reference, presented in an American Chemical Society Rubber Division technical meeting: Effects of Nitrogen Inflation on Tire Aging and Performance. The authors place most of the emphasis in tire aging due to oxidation, along with better pressure vs temperature dependency due to lack of moisture. Regarding permeation, they say: "One benefit of using N2 is claimed to be higher air pressure retention because of the lower permeability of N2 than O2 through IIR, NR, and SBR compounds. While this is true in controlled laboratory tests of pressure retention in tires, the benefit to the real world consumer could be somewhat less. Pressure loss due to leakage around the rim flange seal of the tire to the rim and also the valve seal to the wheel (plus pressure loss through the valve itself) could account for some of the air loss experienced by the typical consumer, for example." Note that they don't say anything about N2 molecules being bigger, and that they treat this as a "claim". I could believe that N2 permeates slower than O2 through rubber because this permeation is not an ideal process (like an ideal gas going through a pinhole), but there is some interaction between the gas and the rubber. Itub 22:04, 22 December 2006 (UTC)

Talking to myself here. I found this paper called The Permeability of Different Rubbers to Gases and Its Relation to Diffusivity and Solubility (full text requires a subscription), and it convinced me that yes, oxigen permeates rubber faster than nitrogen. Also, it is actually true that N2 is bigger than O2, according to a specific definition of molecular diameter based on "internal friction"! As SBHarris said above (as well as the paper on effects on tire aging), there's still the question of whether this is worth paying for, but it turns out that it is a real effect. Sorry if I was too critical, but I think the net effect will be positive: we will have some references to back up these statements. Itub 22:55, 22 December 2006 (UTC)

Sorry I did not answer earlier, I was busy with hydrides and hydrogen sulfide.

No probs about being too critical, maybe I was not critical enough here. And well, it never hurts to have references to back it up, anyway. It is just, normally these tags get added, and noone looks after them, until people start deleting the statements, even while they are true. I see by the way, that I made a mistake earlier, of course oxygen is heavier than nitrogen, which would make oxygen a slower diffuser than nitrogen (purely on molecular weight effects). I guess I need a holiday (less than two days to go)! See you around! --Dirk Beetstra ^{T C} 23:02, 22 December 2006 (UTC)

melting point -210.00'C, boiling point -195.75'C

Is this correct? —The preceding unsigned comment was added by 84.202.209.246 (talk) 13:06, 21 February 2007 (UTC).

Molar mass

I don't know how to add it myself, but I believe it's 28 grams/mol. Could someone whose computer doesn't censor access to the periodic table add the correct number? Thanks. Kalai Eljahn (talk) 16:35, 9 January 2008 (UTC)

change required

according to the upper right figure, Nitrogen has 6 protons...?! —Preceding unsigned comment added by 132.69.253.40 (talk) 14:25, 5 April 2008 (UTC)

I changed the number of protons to 7 using the 7 in the SVG text from 17. There's no 7 available in that position for neutrons in an SVG, so I had to leave it incorrect. --Lucent (talk) 20:18, 4 May 2008 (UTC)

Filling tires with nitrogen

There should probably be a section in this article or a link to a new article about filling tires with nitrogen. Airplanes and race cars use nitrogen and it is becoming more common with street vehicles as well. --Pascal666 (talk) 04:34, 29 July 2008 (UTC)

The article already had this in the Applications section, which was deleted by a vandal four months ago without anyone noticing! I've readded the section. --Itub (talk) 08:15, 30 July 2008 (UTC)

I only see a one-liner. The use in race cars and aircraft capitalizes on Nitrogen's stable volume across a temperature range, whereas regular air contains gasses that expand much more when heated. The use in passenger vehicles is highly questionable, and the practical impacts are disputed. We cite practical impacts for passenger vehicles directly from papers published by a business trying to sell nitrogen filled passenger vehicle tires. --John Moser (talk) 17:16, 10 September 2011 (UTC)

7P6N?

I see on the Nitrogen graphic

http://en.wikipedia.org/wiki/Image:N-TableImage.svg

the entry

7P
6N

which I take to imply ¹³N is the most abundant isotope. If I read that wrong, please correct me. If I read that correctly, IT is wrong! The abundant isotope is ¹⁴N at over 99% with ¹⁵N adding ~0.3%, whereas ¹³N has a half life of <10mins.

So perhaps:

7P
7N

would be more appropriate? I've no idea how to change it. Over to ...? NickSharp (talk) 00:08, 4 October 2008 (UTC)

I went into Illustrator and copied the 7 from above down to the other one, using the positioning of the 6 to position the 7. It's probably about right. It'll take a little while to update here, but the fix should be evident soon. {{Nihiltres|talk|log}} 19:56, 4 October 2008 (UTC)

critical temperature

Could anyone check the critical temperature? i think it is not 15436.21 K but 154.3621 K, similar to the one of oxigen. If it is 15436.21 K liquid nitrogen could be stored at envirnomental temperature. (The above not signed)

The critical point data seem wrong, but I am no expert.

Nist (US National Institute of Standards and Technology) has a couple of data sets with different sources, see http://webbook.nist.gov/cgi/cbook.cgi?ID=C7727379&Mask=4, the table below the heading "Phase change data". It gives, for the most recent data set, 126.19K at 3.3978MPa (actually 33.978 bar) from Jacobsen, Stewart et al. 1989. The oldest data set from 1915 has the critical pressure at 3.0698 bar, but I suspect they have made an error when entering the data into the table, confusing bar and MPa or something. Cacadril (talk) 01:38, 27 November 2008 (UTC)

I now changed the infobox template. Cacadril (talk) 04:24, 27 November 2008 (UTC)

The critical data had been vandalized; thanks for noticing. --Itub (talk) 12:12, 27 November 2008 (UTC)

Explosive section?

There is none and there should be one —Preceding unsigned comment added by Ericg33 (talk • contribs) 08:08, 30 January 2009 (UTC)

N4 in dielectric switches

Molecular nitrogen, a diatomic gas, is apt to dimerize into a linear four nitrogen long polymer (N₄).^{[citation needed]} This is an important phenomenon for understanding high-voltage nitrogen dielectric switches because the process of polymerization can continue to lengthen the molecule to still longer lengths in the presence of an intense electric field. A nitrogen polymer fog can thereby be created.^{[citation needed]} The second virial coefficient of nitrogen also shows this effect as the compressibility of nitrogen gas is changed by the dimerization process at moderate and low temperatures.^{[citation needed]}

The need for a good source is at that para for two years, so I think it should be moved to the talk page.--Stone (talk) 07:05, 16 May 2009 (UTC)

Shouldn't Nitrogen also be in Category:Biology and pharmacology of chemical elements ?

Shouldn't Nitrogen also be in Category:Biology and pharmacology of chemical elements ? Eldin raigmore (talk) 18:18, 16 May 2009 (UTC)

Citations needed in biological role section

Someone has placed loads of tags in the section about biology. I'm going to remove them and replace them with a tag at the top of the section. Looking at the section all the information seems correct, whilst not having citations is a pity having every few words makes it incredibly difficult to read! Smartse (talk) 01:50, 1 September 2009 (UTC)

Possible Vandalism

Hi, everyone. Just now I found that in the basic information box on Nitrogen, the word "Nitrogen" has been replaced with "cody presson". (I can only assume this is a real person, his Facebook is the first result on Google)

The problem is, I can't "rechange" the page at all. Could someone (admin, moderator) help out? Thanks! Illegitimate username (talk) 21:00, 19 November 2009 (UTC)

I figured out the problem was that the template for the infobox hasn't been protected. So, maybe some precautions should be made there? Illegitimate username (talk) 21:06, 23 November 2009 (UTC)

History - Antoine Lavoisier

In the history it says that ""Nitrogen gas was inert enough that Antoine Lavoisier referred"", I suppose this was prior to the discover of nitrogen? ChristianBxx 12:06, 8 January 2010 (UTC) —Preceding unsigned comment added by Christian75 (talk • contribs)

The Daniel Rutherford article makes no note of his calling nitrogen "fixed air." In Elements of Chemistry, Lavosier regularly refers to carbon dioxide as fixed air (the Carbon dioxide article notes that Joseph Black first called it this in the 1750s). If Rutherford indeed called nitrogen "fixed air," it needs to be documented. JKeck (talk) 15:34, 20 January 2010 (UTC)

Edit request from 173.172.106.124, 10 April 2010

{{editsemiprotected}}

The BP of Nitrogen gas should be positive 320 Farenheit not -320 173.172.106.124 (talk) 22:24, 10 April 2010 (UTC)

Nope.  fetchcomms☛ 22:30, 10 April 2010 (UTC)

Molecular Nitrogen bond strength implied weak in this article

Molecular Nitrogen is quite inert. Li,Mg Reactions to the contrary. More important to the average person is NOx formation during (high temp, pressure) adiabatic combustion phase of internal combustion engines. (Why no mention of historic Nitrogen fixation via Cyanamide? (CaCO3 + C + N2 > CaNCN)). Even Argon can displace N2 adsorbed to transition metal surfaces!

Need to mention the strength (bond energy) of N2 triple bond as driving force for many reactions. Orbital sp-sp bonds are an important class (CN-, NO+, et al) for 2nd row elements. Strength of NN bonds show in Molecular Nitrogen (NN+) discharge lasers (Aurora Borealis glow)), Nitrous Oxide, Diazonium compounds, Diazomethane reactions,

High energy of creation for NN triple bond drives NASA thrusters (from Rocket Research Company; NH2NH2 > Iridium Catalyst > N2 + 2 H2). Know that 2 H > H2 is 104 Kcal/mole; what is 2 N > N2 delta E? Shjacks45 (talk) 20:15, 9 May 2010 (UTC)

Did you not read the second paragraph in the lede/lead? This point is also emphasized in the section that deals with nitrogen use in fuels and explosives. I think a few of your other points are not in the article, but feel free to add them in the appropriate places. However, I urge you to READ it carefully first! SBHarris 21:19, 9 May 2010 (UTC)

N2 (NOS)

Hi! I went to the dealership on a day when the temperture dropped, thank God, and my tire pressure was low. The guy at the dealership explained that NOS would be better than Oxygen, which was fine. However, I like to race , every now and then and I have watched all of "The Fast & Furious" movies. NOS can be explosive! They had NOS in thier cars and i just have it in the tires but if I am in an accident, not caused by racing, will my car explode and burn?

Thanks Claudia A. Rodgers —Preceding unsigned comment added by 63.98.103.65 (talk) 21:20, 27 August 2010 (UTC)

NOS is not a gas, it is a brand name belonging to Holley Performance Products. It's an acronym for Nitrous Oxide Systems. You are making the mistake of using nitrogen gas and nitrous oxide gas interchangebly. I'm sure what you have in your tires is in fact, harmless, and inflammable, nitrogen gas--Plasmic Physics (talk) 21:44, 27 August 2010 (UTC).

Popsci

Here is one of those very watchable pop science pieces showing someone demonstrating the Leidenfrost effect by briefly dipping his whole hand into liquid nitrogen. A similar demonstration with molten lead (and a wet hand) was given on Mythbusters by Adam Savage. This may be a useful and very graphic resource for this article. I am also posting about this at Talk:Leidenfrost effect. --TS 22:56, 8 September 2010 (UTC)

Ph₂PCH₂CH₂PPh₂

{{editsemiprotected}}

Fourth para under Reactions, there's a phosphorus missing from the formula of the DPPE ligand. 137.205.222.209 (talk) 12:45, 3 February 2011 (UTC)

I've added it, thanks. --Dirk Beetstra ^{T C} 12:55, 3 February 2011 (UTC)

E941

E941 redirects here but there is no mention in the article of this at all, which may be confusing to people that don't already know the connection. --194.168.49.208 (talk) 15:58, 5 April 2012 (UTC)

• Annoying. E941 should be explained in the text or the E941 article should be deleted. V8rik (talk) 16:55, 5 April 2012 (UTC)

Its in with a book ref. --Stone (talk) 20:53, 7 January 2013 (UTC)

Notes section - volatility?

The notes section states that "Nitrogen and its compounds are far less common in atmospheres of smaller rocky moons and planets than neon, due to it being less volatile than neon." Could someone please clarify this? Lighter gases can escape easier, so in this sense one would expect nitrogen to be more more common. On the other hand, neon has a higher partial pressure due to its lower boiling point, so in my opinion the statement in the note can be true, but in this case the most important factor is the temperature of the planet, not its size. I believe the wording should be improved somehow or a citation given. Szaszicska (talk) 08:04, 11 August 2013 (UTC)

Statement is in error and will be fixed. Nitrogen is less volatile (higher boiling point) and is in fact more common.SBHarris 09:28, 11 August 2013 (UTC)

Solid & Liquid Nitrogen Densities?

(0 °C, 101.325 kPa) 1.251 g/L
0.808 g·cm−3
Completely different measures of densities, in different atmospheres (in order to run it at different temperatures?)
Confusing.
How about density at standard atmosphere (and then tell us the temp it would need to be at).
~ender 2013-09-29 22:35:PM MST — Preceding unsigned comment added by 174.17.43.160 (talk)

Huh? It's the same pressure (standard 1 atm, here in kPa as unit). The temp is clearly stated for gaseous (0 °C) and liquid (melting point) nitrogen. We use g/L for the density of gaseous nitrogen because it's a gas and so the density is so low that only g/L gives you an easily read (without scientific notation) number among the more common density units. Double sharp (talk) 06:35, 30 September 2013 (UTC)

making it better

I've read the article. Don't really know it yet, haven't read all the linked articles. Haven't read much outside.

I can't believe there was so much tire nitrogen chatter on this page. I'm an inclusionist, but that just sounds...off. Even if it's done and even if effective, seems pretty minor. Unless we find it has large economic magnitude, would cut that.

Also monster drinks (ref 40) is going bye bye.

Next step after that is I will read Greenwood. Then Shriver. Then Cotton (basic and advanced).

At some point, I need to copyedit it (the process forces me to read closer).

Org seems decent, better than Chlorine. But I may want to make it closer to the standard WikiProject Elements sections.

Also, need to think about illustration.

71.127.137.171 (talk) 04:37, 13 October 2013 (UTC)

Agree. That stuff about tires and drinks was done by people who think of nitrogen as gas, and the gas as the pure stuff. Of course, all that's very minor. Pure nitrogen gas is used mainly to keep oxygen out. Nitrogen compounds are used in fertilizers, war chemicals, and of course very widely in biology and medicine. Nitrogen is one of those things that is everywhere dispite being quite uncommon in the Earth's crust and quite hard to get out of the atmosphere. SBHarris 05:21, 13 October 2013 (UTC)

REview

History

• By whom and when was nitre discovered and used?
• Was urea part of the history of nitrogen?

Discovery of nitrogen looks OK

• What was later done with the newly discovered nitrogen
• The Linde process and the large scale production of pure nitrogen by distillation.
• The discovery that nitrogen is lacking in the soils and that fertilizers should contain nitrogen compounds
• Nitrogen fixation of plants and the fixation by the Haber Bosch process is a important part

--Stone (talk) 09:56, 20 May 2013 (UTC)

good comments.71.127.137.171 (talk) 03:15, 13 October 2013 (UTC)

Thanks! --Stone (talk) 09:01, 13 October 2013 (UTC)

Organization

Any thoughts on the layout? I sort of like the idea of non-chemical text at the start, but then I also wonder if we should hew closer to the Project Elements style (or Fluorine layout) and have a section on properties at the front. The eutrophication could be handled in an environmental section also. Not trying to push any standardization, just opening discussion...

98.117.75.177 (talk) 15:48, 13 October 2013 (UTC)

Fluorine does it by starting with physical characteristics, then universe origin/abundance/ocurrance, then human history/etymology. Almost any of these three could be used as a first topic after the lede (which of course has to have everything).

If you start "at the beginning" does that mean literally in chronology, and is that the beginning in time, or the beginning in terms of human history? Or does "the beginning" of "what there is to know" about an element, connected with what the stuff looks and feels like at standard temperature and pressure? And is that true even if few people ever encounter it that way? How many people have seen fluorine in pure state, vs. say, gold or copper.

I've only resisted trying to have a universal template for all the elements, since it seems to me that the usual dictim to present the reader knowledge he/she is most likely to want to know FIRST, probably varies from element to element. For some elements we know what they look like and are used for (gold, for example) and are looking for other information. For others elements like gallium or neodymium, even these basics may be mysterious to the average person and so should be discussed earlier. Likewise, some elements have been known so long (even as native elements) that they have wooly histories and etymolgies that have been lost in time. Think of carbon, iron, and sulfur. Others are so new that we know exactly who discovered and named them. Some elements have universe origin and abundance that stands out as one of their most noticiable subtopics (hydrogen, helium, and perhaps neon). One can also argue that you want to know the physical properties of each element (in the pure form) first of all-- but is that really true? Some elements are almost never seen in their pure form or rarely used that way (bromine and fluorine, and some rare earths), so this stuff can wait. Also, there are elements for which discussion of properties of the pure element segues more naturally AFTER the discovery section. Oddly, I think fluorine is one of these, but the authors there have decided to put its properties (which are rather esoteric and not economically nearly as important) up front, there. Some things are not worth arguing.

For all the elements I've tried to keep their biological connection at the end (end of the lede, end of the article), just because life is very complicated and it seems to work better if we save it for last, after we have reviewed as much as possible about the element in every other context. Of course this section is much longer for some elements like C,H,N,O,Ca,P, than it is for the next two dozen elements that are perhaps actively used in some organisms, and finally to the thers that are either active toxins or just bystanders (most but not all inert gases-- xenon is an anesthetic as are also Ar and Kr at pressure!). Anyway, if all this stuff looks nonuniform, it's not because we haven't thought about it. It's rather that the answer is not the same for hydrogen and helium as for silver and gold (say). Or terbium and plutonium.

In any case, I'm open to fixes with nitrogen. Try one way, then another. It seems to me that the history of nitrogen use breaks naturally at the 20th century when scientists learned to artificially fix it, and it became the major player in war and peace that we know it as, today. But all of that is history of nitrogen compounds. Nitrogen as an element is almost an inert gas until it happens to contact lightening, nitrogenases, or human nitrogen fixation technology (which again is only about a century old). So it has a double role that can resist fluid transitions in writing. SBHarris 19:38, 13 October 2013 (UTC)

1. I am strongly in agreement at resisting a universal template for your same reasons.

2. Talk to me a little more about fluorine. What would be your preferred order then? Give me the whole rundown. I looove the idea of having more engaging text to keep the English majors in the game. would you go:

• history
• occurrence
• characteristics
• compounds
• industry
• bio
• hazards
• enviro

??

3. Thanks. On Nitrogen, I really want to do what you said (try different structures). It's how I learn and engage. Just was trying to avoid version control struggles or the like (is easier to play with something when writing on your own).

71.127.137.171 (talk) 21:00, 13 October 2013 (UTC)

fluorine org

How about occurrence/history/characteristics as an order? After all the properties of the savage beast were not well known until after Moissan isolated it, so why not have it right after? (I will have to work on layout as well, the pics versus the infobox and all that.)71.127.137.171 (talk) 21:25, 13 October 2013 (UTC)

History and Etimology

The etimology of Nitrogen is not correct, what is reported is a mixture of fantasy and chemistry knowledge, but it is not the right etimology of the word "Nitrogen". It comes literally from the ancient term "Neutro-genus", which means "generator of the Neutro force", distinguished from the "Oxy-genus",generator of the "Active-force" (oxy= from the greek "sharp,the effect of fire,corrosion") and from the "Hydro-genus", generator of the "Passive-force"(Hydros=water, opposed to fire, principle of passivity). It is more complex than i'm able to explain, but in a few words that's the question.

You are wrong. Chaptal named it nitrogene (nitric acid maker) because it forms the radical (unoxidized part) of nitric acid, as Chaptal well knew. He is the one who named it, and he says WHY he did: http://www.wordorigins.org/index.php/more/1239/

In English, nitrogene because nitrogen. Nitric acid is of course from nitre, an old and unclear word for many minerals, and probably related to natron. But only the special kind of nitre that could produce nitric acid, contained Chaptal's gas. SBHarris 04:42, 4 November 2014 (UTC)

Nitrogen gas

Dinitrogen and Nitrogen gas redirect to this page, although the atomic element and the N2 molecule are two different concepts (see https://www.wikidata.org/wiki/Q2370426 for the molecule). At the moment we can't create an interwiki link from the French Diazote page to the English page because of this. Could someone please create an independant Nitrogen gas article? My english is not good enough to do it myself. PiRK (talk) 07:07, 1 December 2014 (UTC)

External links modified

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Solid nitrogen

An article on solid nitrogen has just been moved to main space and this article should probably link to it. EdChem (talk) 14:24, 30 April 2016 (UTC)

 Done You can add please some words ... --Alchemist-hp (talk) 14:32, 30 April 2016 (UTC)

Plz change picture, i wanna know what it looks like but i feel like the container is affecting the appearance,, for my stupid ADD visual is more important then words (guessing while your at it,, might wanna combine videos to wikipedia lol.. i just gave you a huge EXTREMELY importance and amazing idea for making all retards learn easier,, just connect videos (im guessing videos accecible and free to all, and plz good luck on making attractive clear smart simple,, videos to me are 100X better cause i can listen to the audio in loop without watching while doing anything else (i used it like a brain wash when i get bored) and since i can reduce the video quality,,, i might be able to use it during gaming,, ya i know im a genius now whos gona be capable of amazing attractiveness, no offencive context plz, relevent clear and simple description of your videos (the exact opposite (of me) of my problem lol) you need the best and smartest teachers to make my idea live,, i tried wikia but i fkin hate the publicity enforcement, its so wrong at so many levels to penalize someone who wants to learn,, and in the future videos are the best ways to make knowledge easily accecible to all,, (whats gona be fkin hard is the conception) i cant tell all the details obviously i need a sample to be able to clearly criticize (but a teacher with AMAZING motivation i learned can teach me the most anoying and boring stuff) they are def worth more then diamonds (you can erase my text paragraph when yu read and felt it was heard or wtv reasons just dont let it go to waste), i dont want to bother too many people with this paragraph but ive been waiting too long for anyone to think of my idea, and i figure since wikipedia is such an amazing source of information why isnt there any videos (even if they are short to start with) (oh and plzzz get to the future,, THE MOVING PICTURES gifs, been a while i saw how the future will look (harry potter pictures on shelves),, now that i actually can see a sample of the most brilliant people creating GIF's!!!, i know everything should be made out of it (EVERY SINGLE PICTURE, aight ok more then 80%, still cant believe mobiles dont have that, hey thinking about it the idea of gif is actually a restriction of a video to a shorter rule version (like tweater? i have no idea how tweeter works so, but im pretty sure thats what it looks like),, like when your pooring the liquid nitrogen inside the cup (does it vapor how fast the liquid touch the cup does it look oily or goowy or watery, touch it with something (frozen popsicle? xD etc, i wanna be able to feel it trough with my eyes since i cant touch it sadly (frozen fingers xD?) — Preceding unsigned comment added by 96.21.215.21 (talk) 18:26, 23 August 2016 (UTC)

Semi-protected edit request on 20 November 2016

Goodmorning. The Critical point in the lateral table is 126.192 K, 33.958 MPa, NOT 126.192 K, 3.3958 MPa. The pressure is wrong.

Thank you. Mithrandir90 (talk) 20:26, 20 November 2016 (UTC)

Negative, the pressure is correct. Materialscientist (talk) 00:16, 21 November 2016 (UTC)

GA Review

This review is transcluded from Talk:Nitrogen/GA2. The edit link for this section can be used to add comments to the review.

Reviewer: Jclemens (talk · contribs) 20:04, 30 November 2016 (UTC)

Rate	Attribute	Review Comment
1. Well-written:
	1a. the prose is clear, concise, and understandable to an appropriately broad audience; spelling and grammar are correct.	Still thinking and discussing this Fine after revision
	1b. it complies with the Manual of Style guidelines for lead sections, layout, words to watch, fiction, and list incorporation.	Fine.
2. Verifiable with no original research:
	2a. it contains a list of all references (sources of information), presented in accordance with the layout style guideline.	Fine.
	2b. reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose).	Fine.
	2c. it contains no original research.	Fine.
	2d. it contains no copyright violations or plagiarism.	None identified (one YouTube text mirror of our article excluded)
3. Broad in its coverage:
	3a. it addresses the main aspects of the topic.	Absolutely
	3b. it stays focused on the topic without going into unnecessary detail (see summary style).	If there's an Achilles heel in the article, this might be it, but I think we're at the maximum we can do to promote readability without losing information.
	4. Neutral: it represents viewpoints fairly and without editorial bias, giving due weight to each.	No issues noted.
	5. Stable: it does not change significantly from day to day because of an ongoing edit war or content dispute.	No issues noted.
6. Illustrated, if possible, by media such as images, video, or audio:
	6a. media are tagged with their copyright statuses, and valid non-free use rationales are provided for non-free content.	Looking at "File:Nitrogen electrode potentials.svg", it's not clear to me why a copy of a table extracted from a copyrighted, published work can be said to be appropriately free to use. (Addressed below) Everything else looks fine.
	6b. media are relevant to the topic, and have suitable captions.	Fine.
	7. Overall assessment.	Once again, detailed work to bring such a technical article to GA status!

I'm pretty sure the table copy should be okay, because you cannot really copyright data like that. Usually (like in chlorine) I put it in tabular form, but here there are many species and things are very complicated. I don't think the presentation of the data reaches the threshold of originality because arrows are pretty obvious and so is a listing by oxidation state. Double sharp (talk) 03:51, 1 December 2016 (UTC)

Sorry for the slower-than-usual progress. Keep the page watchlisted, and I'll get through it with meaningful feedback. Jclemens (talk) 18:57, 3 December 2016 (UTC)

First read through

• "The extremely strong triple bond in elemental nitrogen (N≡N), the strongest bond in any diatomic molecule, dominates nitrogen chemistry, causing difficulty for both organisms and industry in converting N2 into useful compounds, but at the same time causing release of large amounts of often useful energy when the compounds burn, explode, or decay back into nitrogen gas." That's an awesome sentence, but I think it would be better as two or three.
  •  Done Double sharp (talk) 07:44, 4 December 2016 (UTC)
• Lead is five paragraphs. Does it need to be that long? I may have more concrete ideas on that later.
  • Now four. Double sharp (talk) 07:46, 4 December 2016 (UTC)
• "Plant alkaloids (often defense chemicals) contain nitrogen by definition, and many notable nitrogen-containing drugs, such as caffeine and morphine, are either alkaloids or synthetic mimics that act (as many plant alkaloids do) on receptors of animal neurotransmitters (for example, synthetic amphetamines)." I'm sure there's a better way to do that with fewer parenthesis.
  •  Done Double sharp (talk) 07:46, 4 December 2016 (UTC)
• The lead appears to cover chemical properties and periodic table position before history, while the article itself seems to address these in the opposite order. I suspect they should be ordered similarly, whichever topic is to be addressed first.
  •  Done Double sharp (talk) 07:42, 4 December 2016 (UTC)

History

• "The discovery of nitrogen compounds has a very long history, ammonium chloride having been known to Herodotus." Awkward. Nitrogen has a long history or nitrogen compounds were discovered long ago, but a history of discovery seems an inelegant way to address the topic.
  • How about "nitrogen compounds have a very long history"? Double sharp (talk) 07:40, 4 December 2016 (UTC)
• "The existence of nitrogen is formally considered to have been discovered by..." formally considered by whom? This seems wordy. "The discovery of nitrogen is attributed to..." seems like it would work as well. Why does it need four citations without in-text elaboration?
  • Removed the dead links (which seem to have been just repetitive), leaving just Rutherford's original paper and Weeks as a modern historian surveying it. Double sharp (talk) 07:40, 4 December 2016 (UTC)
• "This "mephitic air" consisted mostly of N2, but might have included more than 1% argon." Trivia. Uncited. Of what significance? Sounds better suited to Lavoisier's article.
  • Indeed mostly insignificant and would be better placed in the Ar article (along with Cavendish's astoundingly accurate statement that there was an inert component of air comprising "not more than 1⁄120th part of the whole", which turned out to be argon.) Double sharp (talk) 07:38, 4 December 2016 (UTC)
• Cool to get the etymology of pnictogens here. Not sure if the term should be introduced in the lead or not, absent this explanation.
  • Added the explanation to the lede. Double sharp (talk) 07:59, 4 December 2016 (UTC)
• The last two paragraphs of history feel like they need expansion and maybe should be covered in detail elsewhere. These are pretty significant events that are let off with a sentence or two.

Properties

• Oxygen, Fluorine, and Chlorine appear to be ordered by atomic number, since their ordering is neither alphabetical nor by Pauling scale number. Might want to make the ordering explicit.
  • Since we were just talking about electronegativity, I've changed it to follow that order (Cl 3.16, O 3.44, F 3.98). Double sharp (talk) 06:27, 4 December 2016 (UTC)
• "Following periodic trends, its single-bond covalent radius of 71 pm is smaller than those of boron (84 pm) and carbon (76 pm), while it is larger than those of oxygen (66 pm) and fluorine (75 pm)." Is that last 75 pm for fluorine right? Sure looks larger than 71, rather than smaller.
  • Yes, my mistake: it is actually 57. Double sharp (talk) 06:27, 4 December 2016 (UTC)
• "Ionic radii of 16 pm and 13 pm respectively have been published for the N3+ and N5+ cations, but these must be taken as purely notional figures as simple cationic chemistry is unknown for nitrogen due to its high ionisation energies: the first three ionisation energies of nitrogen are 1.402, 2.856, and 4.577 MJ·mol−1, and the sum of the fourth and fifth is 16.920 MJ·mol−1." Why include theoretical numbers like this, with so much commentary? We deal with theoretical numbers all the time without needing to explain that they haven't been observed in nature... at least not at such length.
  • Since N³⁺ and N⁵⁺ are really just impossible, I've simply removed them and just left the ionisation energies to explain that N has no simple cationic chemistry. (Even further down the group, neither do P, As, and Sb; Bi is the first pnictogen that actually exhibits "real" cationic chemistry in Bi³⁺.) Double sharp (talk) 06:42, 4 December 2016 (UTC)
• "This far to the right of the periodic table, the diagonal relationship with sulfur has with only a few exceptions faded completely into insignificance." How do I understand this without following the link?
  • In the first two rows of the periodic table, elements that are diagonally next to each other (northwest-southeast) tend to be similar. For instance, the pairs Li–Mg, Be–Al, and B–Si are very similar to each other, and in fact Li, Be, and B have more in common with these diagonal neighbours than to their actual vertical neighbours. But then this drops off abruptly, with the C–P relationship being more restricted to organic chemistry (IIRC there's a book with the amusing title Phosphorus: The Carbon Copy). By the time you get to N–S, you really do not see any relationship outside the cyclic sulfur nitrides. Finally we reach the pairs O–Cl and F–Ar when there are no similarities to speak of.
  • I've changed it to "Although each period 2 element from lithium to nitrogen shows some similarities to the period 3 element in the next group from magnesium to sulfur (known as the diagonal relationships), their degree drops off quite abruptly past the boron–silicon pair, so that the similarities of nitrogen to sulfur are mostly limited to sulfur nitride ring compounds when both elements are the only ones present." Double sharp (talk) 06:42, 4 December 2016 (UTC)
• "14N is one of the five stable odd–odd nuclides (a nuclide having an odd number of protons and neutrons); the other four are 1H, 6Li, 10B, and 180mTa.[24]" Shouldn't the superscript before H be 2, rather than 1?
  • Yes. Corrected! Double sharp (talk) 06:42, 4 December 2016 (UTC)
• Do the discussions of NMR and nuclear power belong elsewhere? Should they maybe be labeled separately? Frankly, each is a bit obscure for me as a layman, and I'm not entirely sure what each paragraph means.
  • These don't seem relevant to any other section since they directly relate to the different N isotopes. The NMR thing is mostly useful for ¹⁵N (which has some problems; it's used because ¹⁴N is even worse, but it is already quite bad because it's rare, and even when you enrich it you face the other problem that its signals are weak and tend to get drowned out), and the nuclear power thing is just a cool thing where one of the short-lived N radioisotopes is important (¹⁶N is formed in the water used in nuclear reactants, so if you find it outside you know immediately that there has been a leak). Double sharp (talk) 07:58, 4 December 2016 (UTC)

Chemistry and Compounds

• "It is prepared by passing an electric discharge through nitrogen gas" 'It' is atomic nitrogen, right?
  • Yes. Edited. Double sharp (talk) 06:43, 4 December 2016 (UTC)
• "The bonding in N2 is characterised by overlap between the 2s orbitals to give occupied σ2s (bonding) and σ*2s (antibonding) orbitals (which therefore cancel out and have no net contribution to the bond order), a head-on overlap between one of the p-orbitals on each nitrogen atom to give the σ2p bonding and σ*2p antibonding orbitals, and side-on overlap between the other two p-orbitals of each nitrogen atom to form the two π2p bonding and two π*2p antibonding orbitals." This may make perfect sense to people with more chemistry background than I have, but if I've done general chemistry series within the past 10 years and can't make head or tails of the sentence even though I'm quite familiar with electron shells, I suspect it's a bit arcane and/or could be explained better.
  • The idea here is to explain why nitrogen is so unreactive as N₂, which I got to at the end of the paragraph (although maybe I should have started with that at the beginning). I think a picture is badly needed... Double sharp (talk) 07:04, 4 December 2016 (UTC)
  • OK, I have added an MO diagram with my lame MS Word AutoShape skills. I also added a long explanation (qualitative only: mathematically what you are doing is making linear combinations of the 1s, 2s, and 2p orbitals of each N atom, but it's easier to think of it as overlap, which is how everyone teaches it.) Double sharp (talk) 07:15, 4 December 2016 (UTC)
  • Sigh...this is really hard to do without sounding like a textbook. I've reverted it to the original first, but with the diagrams showing the shapes of the orbitals (which I hope explains what "head-on" and "side-on" mean for the 2p orbitals), and the MO diagram showing the bonding. I hope it helps a little. Unfortunately I don't see a way to make it clear without hijacking it with a discussion of MO theory, so instead I've linked to that. Double sharp (talk) 07:32, 4 December 2016 (UTC)
• "There are some theoretical indications that other nitrogen oligomers and polymers may be possible." And here we go again with some pretty dense theory which doesn't well explain why any of this matters.
  • Well, I did write as the second sentence of that paragraph "If they could be synthesised, they may have potential applications as materials with a very high energy density, that could be used as powerful propellants or explosives." Double sharp (talk) 07:15, 4 December 2016 (UTC)

... And that's where I'm going to call it and stop for tonight. This article appears to have a larger ratio of detailed chemistry observations to practical application than Iron does. Jclemens (talk) 02:27, 4 December 2016 (UTC)

I've tried to delete a few more things (e.g. the bonding description, which is covered in the image anyway) and some of the more unstable theoretical N allotropes (they are not expected to be all that stable anyway). Double sharp (talk) 02:04, 14 December 2016 (UTC)

Continued...

So, you've done so much since last I wrote, that I'm going to back up to Chemistry and Compounds and see what I see from there. Again, I apologize for my slowness in reviewing.

It is no trouble, especially since I am currently on holiday and am editing from my phone! Double sharp (talk) 01:54, 14 December 2016 (UTC)

• "In particular, since the B–N unit is isoelectronic to C–C, and carbon is essentially intermediate in size between boron and nitrogen, much of organic chemistry finds an echo in boron–nitrogen chemistry, such as in borazine ("inorganic benzene"), although the analogy is not exact due to the ease of nucleophilic attack at boron." The final clause could be made into a separate sentence and explained more fully.
  •  Done - I hope comprehensibly. Double sharp (talk) 01:58, 14 December 2016 (UTC)
• Overall, through this whole section, I feel like I don't know enough chemistry to understand precisely what the article is describing.
• I'm wondering about mixing in the practical with the chemical. The article discusses something, and at the end after less educated readers' eyes will have glazed over, discusses the practical aspects of whichever nitrogen-containing compound in a relatively straightforward manner.

I've tried to remove some of the more incomprehensible details about various N-containing compounds as ligands, leaving only that for N₂ itself. Double sharp (talk) 05:48, 14 December 2016 (UTC)

Occurrence and Production

• These sections seem really, really short compared to the preceding section.

  Mostly because while N has a very rich chemistry, there was never any need to come up with complex ways to extract it because air is already a 78% pure N sample that is essentially inexhaustible. There is also not much cause to make it in the lab since liquid N₂ is so easily purchased. All of this combined means that there isn't much to say. The Haber process is already somewhat off-topic as it's not making nitrogen, but using nitrogen to make ammonia. Double sharp (talk) 05:52, 14 December 2016 (UTC)

Safety

• The section on Liquid safety contains elements that are substantially redundant to the preceding discussion on e.g. asphyxiation via O2 displacement.
  • Addressed, I think. Double sharp (talk) 05:56, 14 December 2016 (UTC)

Overall, I think I need to go over this again, but my general impression is that there's some simple, straightfoward application text buried within an article that becomes very arcane and technical. I'm thinking about how to improve the readability... Jclemens (talk) 21:16, 11 December 2016 (UTC)

I'm still here, just with less Wikipedia time than I'd expected. I hope to give more substantial feedback over the next 48 hours. Jclemens (talk) 03:22, 20 December 2016 (UTC)

From the top again...

• "Although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first." This should probably explicitly state 'discovered', preferably in a non-redundant way.
• Let's think about the disconnect between the lead and the rest of the article. The lead, as it stands now, is awesome and accessible; I really like how it focuses on the 'so what?' of nitrogen's effect on our lives. About the only thing I think could be added to the lead is a tidbit about laughing gas/nitrogen narcosis. However, most of the rest of the article seems to be of the "cool scientific fact with lots of detail requiring at least a chemistry minor to understand"->"Common, practical application". Can we reverse the polarity? ;-)
• History, Properties, Occurrence, Production, Applications, and Safety No further comments, these are GA quality as is.
• "Given the great reactivity of atomic nitrogen, elemental nitrogen usually occurs as molecular N2, dinitrogen." Is 'usually' and understatement? Would 'almost exclusively' or some similar phrasing be more appropriate, or am I misunderstanding what is meant by elemental nitrogen?
• I fixed a thing or two myself. Jclemens (talk) 19:31, 21 December 2016 (UTC)

@Double sharp: to make sure he's looking at this review. Hanif Al Husaini (talk) 10:00, 25 December 2016 (UTC)

I am indeed looking and editing. It won't be perfectly understandable alas because some of these compounds (like P₃N₅) don't yet have known applications outside chemistry (research is ongoing), but I've tried to add more of those to show how nitrogen compounds are used. (I should note that if one clicks on all the links it should become possible to understand it without a chemistry degree. ^_^) Double sharp (talk) 10:02, 25 December 2016 (UTC)

OK, I think I've improved it as much as it could plausibly go with the moving of applications to the front (though perhaps it might have been a little better at the back, because if you skipped over the middle of the paragraph with the chemical information you'd only look at the beginning and the end).

I should note that the way I see it, the lede should indeed be understandable to everyone as it is the "simplified" version which everyone is going to read, but the individual sections can be more technical. I would not like cutting out useful information, even if it is only useful to the specialist, since we are supposed to cover all human knowledge, after all, and I think we'd all agree that the chemistry of nitrogen is one of the most important things to have in an article about nitrogen. Double sharp (talk) 10:16, 25 December 2016 (UTC)

I agree about the lede. I'm around tonight and will give this another go-through. Always remember that other than things mentioned specifically in the GA criteria, the rest of my suggestions are that--and you're free to disagree, propose alternatives, or say "I can't figure out how to make it any better" and if neither one of us can, then I suppose it's as improved as we can make it. Jclemens (talk) 00:48, 26 December 2016 (UTC)

OK, other than cite #53 getting broken in the editing process, I don't see any further suggestions for improvement. I didn't see an immediately obvious fix, so I'll let you address it, but that's as accessible as I think you can make it without losing info. Jclemens (talk) 01:06, 26 December 2016 (UTC)

So, looks like that got fixed and/or my cache was just broken. I don't see much more to do here, so let's call it GA. Jclemens (talk) 00:16, 5 January 2017 (UTC)

Thank you! Double sharp (talk) 02:23, 5 January 2017 (UTC)

Abundance

I'm confused by this sentence in the opening paragraph. "On Earth, the element forms about 78% of Earth's atmosphere and is the most abundant uncombined element." Does that mean "most abundant" on Earth or just in Earth's atmosphere? Later, under Occurrence, the article states it has an "overall low abundance in the makeup of the Earth." Therefore I'm going to edit the lede paragraph for clarity. Editor B (talk) 14:24, 2 November 2016 (UTC)

The key is in the word "uncombined". Other elements are more common on Earth, but only as compounds. (For instance, although aluminium and iron are very common, you can't have them uncombined on Earth except in exceptionally reducing conditions.) Nitrogen on the other hand is ubiquitous as the pure element in the atmosphere, even if it isn't so common in the Earth's crust. Double sharp (talk) 14:32, 2 November 2016 (UTC)

I have now made this clearer by adding the following sentence to your version of the lede: "It [nitrogen] is also the most common uncombined element on Earth, since all the more common elements occur primarily as compounds." Double sharp (talk) 14:34, 2 November 2016 (UTC)

Thank you, well done. I'm learning a lot today. Editor B (talk) 14:36, 2 November 2016 (UTC)

You're welcome! Double sharp (talk) 14:38, 2 November 2016 (UTC)

(The reason this was not yet in the rest of the article is that I rewrote the lede first. Now the rest of the rewrite is finished and in mainspace!) Double sharp (talk) 02:59, 23 November 2016 (UTC)