Talk:Neptunium/Archive 1

Untitled
Article changed over to new WikiProject Elements format by mav 08:13, 13 Jan 2004 (UTC). Elementbox converted 11:03, 17 July 2005 by Femto (previous revision was that of 10:56, 14 July 2005).

Synthetic element?
I assume Plutonium isn't a synthetic element because "While almost all plutonium is manufactured synthetically, extremely tiny trace amounts are found naturally in uranium ores." (ref). So why, when "Trace amounts of neptunium are found naturally as decay products from transmutation reactions in uranium ores" (ref), is this element listed as a synthetic element? TerraFrost 02:35, 28 Feb 2005 (UTC)

i am not an expert in that field. but Np, together with Pu, have been classified as synthetic elements due to their radioactive properties. from what i remember, i have been told that elements which are heavier than uranium are mostly unstable and are produced mainly from nuclear reactions. u shouldn't be looking at their natural abundance, but the production method instead.


 * This looks more like an example of info from old sources before natural Np and Pu were found. Kuratowski&#39;s Ghost 08:42, 16 October 2006 (UTC)

Ausonium
Ausonium redirects here. What is ausonium named after? --Error 23:22, 3 February 2007 (UTC)

Pictures Pictures please?
Can someone put in a picture of what Neptunium looks like? probably as either a liquid or solid? I want to know how this looks like please? —Preceding unsigned comment added by Blueknightex (talk • contribs) 10:11, 8 May 2008 (UTC)


 * Done, --Error 00:58, 6 February 2007 (UTC)

Synthetic?
Why does the information box thing claim that Neptunium is synthetic when it DOES exist in trace amounts in nature? --Ferocious Flying Ferrets 02:58, 16 March 2010 (UTC)

Image for infobox
For me the image is terrible! It looks like a computer graphic.--Stone (talk) 18:38, 18 March 2010 (UTC)
 * We can use this one. Do you think its better? Materialscientist (talk) 23:34, 18 March 2010 (UTC)
 * Much better. This is reality and not a thing looking like a T1000. --Stone (talk) 11:02, 19 March 2010 (UTC)
 * Yes, and lucky it is: with the discovery of a PD image, the fair use rationale for the current one becomes invalid. William Avery (talk) 11:09, 19 March 2010 (UTC)
 * Update and deleted "my" previous fair-use image (didn't know about this picture then). Materialscientist (talk) 11:17, 19 March 2010 (UTC)
 * Sorry, for the harsh critics on your image, but the new one is much better.--Stone (talk) 13:20, 19 March 2010 (UTC)

Original Discovery?
http://www.time.com/time/magazine/article/0,9171,747508,00.html This article was from the year 1934 and it states that fermi discovered element 93. However here it says that it was discovered 6 years later. which is correct? —Preceding unsigned comment added by 97.83.174.63 (talk) 20:32, 7 November 2010 (UTC)


 * This is the announcement discovery of the non existing ausonium, neptunium had to wait another six years.--Stone (talk) 22:04, 7 November 2010 (UTC)

Oxidation states
Why does the article act like Neptunium has only four oxidation states, III through VI? Neptunium not only assumes oxidation state VII, there is even a picture of the Neptunium VII in solution!Syd Henderson (talk) 00:54, 6 April 2011 (UTC)
 * The article is undeveloped, help us if you can. Materialscientist (talk) 00:58, 6 April 2011 (UTC)

Weapons of mass destruction
"research for a United States of America weapons of mass destruction development program"

While this could be successfully argued to be a fair and equivalent use of the term "weapons of mass destruction," a term normally applied to programs pursued by rogue nations, its use here is both awkward and politically-charged. It is awkward because the conventional terms used to refer to such scientific study in this country, most notably by the press, fall along the lines of "nuclear research program," "chemistry research program," and "physics research program." Use of the term "Weapons of mass destruction development program" in this context is also politically charged. It comes across as a tacit condemnation of the research described because the use in this context indicates that the author perceives a double standard in the conventional application of the term in today's society. The author seems to be using it here to make a political point about something wholly unrelated to the topic of the article. This should be remedied at once should a more authoritative contributor concur with my assessment.


 * I am not authoritative in any way but would like to make a comment anyway (though too late apparently). Your problem seems to be that '"weapons of mass destruction," [is] a term normally applied to programs pursued by rogue nations'. By itself the term obviously doesn't have that meaning or connotation (it is about weapons, not about who is persuing them), but it has, in certain circles, acquired that meaning. So you are arguing, successfully apparently, that the statement should be removed not because it is incorrect but because there are people who choose to read a different (and obviously biased) meaning into this term, while at the same time claiming that the author is responsible for that?
 * While I would agree the author may have taken advantage of certain peoples' prejudice to make a point, I don't think Wikipedia should censure authors for using words with their proper meaning, regardless of the existence of people who choose to default to a more biased definition of those words. AlexFekken (talk) 05:30, 11 June 2011 (UTC)

Most mobile actinide?
What does it mean that neptunium is "mobile"? Is this a reference to its Permeability (earth sciences)? Whatever is meant by mobility, I think we should provide a link to it. Rwflammang (talk) 21:19, 22 September 2011 (UTC)

There is a factual error in the vector image.
I have tried contacting both authors (Pumbaa80 and GregRobson, 10 Nov. and 12 Nov. respectively) and I have still not gotten any answer. The message was: "Hello,

This vector image that you made (http://en.wikipedia.org/wiki/File:Electron_shell_093_Neptunium.svg) states that the electron configuration of neptunium is [2,8,18,32,22,8,2], this information is false, as it's real configuration is [2,8,18,32,22,9,2] a simple proof if you are skeptical, add up the electrons in the first configuration, you get 92, which implies that Z=92, which is a uranium atom, which is not the case; add up the second configuration you get 93, which implies that Z=93 which is the real deal, neptunium atom.

Please sir, I urge you, as author of the image, to be kind enough to fix the issue. Thank you for your time.

Thank you in advance. Anonymous."

Please,could any good vector artist fix it? Or at least tell me how to fix it? Of course with permission if needed.

Thank you in advance.

62.84.91.6 (talk) 18:04, 16 November 2011 (UTC)
 * Fixed, thanks. Materialscientist (talk) 07:28, 23 November 2011 (UTC)

Error?
"and the primary products after are element 93 (plutonium) isotopes" This reads like element 93 is Plutonium, but Plutonium is 94. (12.41.204.3) -- fixed that Femto 12:24, 9 December 2005 (UTC)

There is a contradiction in two areas of the page... Under characteristics it states that Neptunium is NOT absorbed through the digestive tract. However, in the Biological Role and Properties it states that it IS absorbed through the digestive tract. Not being a chemist or physicist, I am unable to state which of these are factual. Please, could someone correct this?
 * This article is currently undergoing a major rewrite at User:Thingg/neptunium by me and Thingg. Hopefully shortly this improved version will be put on the main page. We have noticed the contradiction and are attempting to find sources to see which is right: I don't know yet. Double sharp (talk) 11:54, 31 May 2014 (UTC)

Please check a couple of sentences
Characteristics / Physical: "The accepted standard value for its density of 19.38 g/cm3 lies between those of its neighbours uranium (18.95 g/cm3) and plutonium (19.84 g/cm3), as does its melting point of (639 ± 3) °C, below that of uranium (1132.2 °C) and above that of plutonium (639.4 °C). This shows the continuity of trends in physical properties across the actinides." The values given for melting point are identical within experimental error so do not show a continuity of trend across the actinides. This description should reflect the statement later in the same section: "Neptunium has been determined to melt at 639±3 °C: this low melting point, a property the metal shares with the neighboring element plutonium, is due to the hybridization of the 5f and 6d orbitals and the formation of directional bonds in the metal." This description of melting points is more-or-less repeated in the two paragraphs, perhaps some further tidying up is necessary. --Mirokado (talk) 23:35, 25 July 2014 (UTC)
 * Removed mention of m.p. and b.p. from the bit talking about continuity of trends. I'm not exactly sure what to do with that – 19.38 g/cm3 may be the accepted standard value, but the most common allotrope (alpha) has a higher density than both U and Pu. Probably I should excise that altogether, so I did that.
 * I've also moved the later workability, m.p. and b.p. material up next to the metion of Np's high bulk modulus. Double sharp (talk) 07:20, 26 July 2014 (UTC)
 * Much better, thanks. --Mirokado (talk) 21:33, 27 July 2014 (UTC)

A quick review
I will give a detailed review during this fall, as promised. Just a quick read for now:

"Although the boiling point of neptunium is not empirically known, the currently accepted value of 4174 °C is from an extrapolation of the vapor pressure of the element. " it'd be better to reword this.
 * ✅ Double sharp (talk) 20:45, 9 August 2014 (UTC)

Alloys: first para reads like a generalization for actinides, not just Np, that's not too good. Instead, try going like "Neptunium, like many other actinides" or the like.
 * ✅ Double sharp (talk) 20:45, 9 August 2014 (UTC)

"−268 °C (4.9 K)" -- Celsius deserves one digit after decimal period as well
 * ✅ Double sharp (talk) 20:45, 9 August 2014 (UTC)

"the ground state term symbol is 5I4" -- is this needed?
 * Term symbol says that this is easily calculated from the ground-state electron configuration, so I don't think it is necessary. So I've removed it. (It might be useful for the transactinides, though, when the SO and subshell splitting is strong enough that the rules may not work. But I doubt Np is at that stage yet.) Double sharp (talk) 20:45, 9 August 2014 (UTC)

"225.0339 u (225Np)" -- isn't it clear 225.03 u is the mass of 225Np? (a real question, not a rhetorical one)
 * I left it that way because I wasn't sure it would be clear for everyone. I mean, it's guessable if you know what order of magnitude the mass discrepancy due to nuclear binding energy is, but that can't be guaranteed for all our readers. (Or did I write that? I don't think I did, but can't remember and don't feel like looking in the history for something like this. It's a collaboration, after all.) Double sharp (talk) 20:45, 9 August 2014 (UTC)

"any primordial neptunium should have decayed by now. After only about 80 million years, the concentration of even the longest lived isotope, 237Np, would have been reduced to less than one-trillionth (10−12) of its original amount." And you only say about what would happen after 80M years, not 14 billion years. I'm too lazy to calculate how much neptunium could there ever be, but you can show this more clearly: after two billion years, there would be <10^(-240) of original amount, so it all should've decayed given the Universe has 10^80 atoms only.
 * I suspect the 80M year figure is because of 244Pu, the most unstable primordial, which has this half-life. So it brings up the point of the half-life blip at Np. (There's also blips at Pa and Am. I always wondered what the story behind the Th–Cm island of stability was, given that there's no magic number here, the usual justification for SHEs. But I digress!)
 * I think the better figure is actually 4.6G for the Solar System's formation, given that that's what's usually meant by the "primordial" in primordial nuclide. So if the whole Earth was initially made of pure 237Np, about 2100 (2 s.f.) half-lives have passed since the formation of the Solar System. 2−2100 = 0 to all intents and purposes. Think this illustrates the point in an easier-to-grasp way. Double sharp (talk) 20:45, 9 August 2014 (UTC)

"should be similar to manganese or rhenium" -- maybe use "and"?
 * Yup. Tc doesn't fit as well into the story, even though I read somewhere that Segrè participated (later) because he discovered Tc, which was supposed to be homologous to Np, and would thus be an expert on its chemistry. Changed to "should be similar to the group 7 elements, such as manganese and rhenium" (because at this point Tc hadn't yet been discovered). Double sharp (talk) 20:45, 9 August 2014 (UTC)

Again, as I said, that would be a quick read during the fall, but I can tell the History section is not too easy to give a quick read (despite being interesting). I suggest smaller paras. And it is also huge, huuuuuge. Consider shortening it.
 * I thought about it as well. The trouble I saw was that the history of Np, if you want to talk about the pre-discovery and discovery, is really the history of the road to the transuranium elements. Once Np was discovered, Pu could be readily discovered (and it was the next part of the story: I have no idea why actinide splits the discoveries at Np, given that Np leads immediately onto Pu) and it then stole all the limelight. After that the methods were good enough to get up to Fm and Md. And since Np was the first of the transuraniums, most if not all of the claims were for it and not the higher elements: so I'm really loath to move most of this out, because it does relate to Np above all. Tried to cut the paras up a little bit. To do any more I'd have to unbundle the citations and read to see exactly which point supports which, which I don't really have the time to do at the moment. Double sharp (talk) 20:45, 9 August 2014 (UTC)
 * P.S. I've changed the actinide article to split the discoveries at U instead of at Np. It seems more logical to me. Double sharp (talk) 19:16, 12 August 2014 (UTC)

Okay, possible ways to get Np are clear, but which are used most commonly? If all, say so. If only one or two, say so, and think if others are needed. :)

"As it has a long half-life of 2.144 ×106 years" -- purification is more of a story, you can easily go with "slightly exceeding 2 millions years," that'd be better for this section I think, wouldn't sound too techy.
 * ✅ Double sharp (talk) 20:45, 9 August 2014 (UTC)

The section on compounds is too inflated, I think. Neptunium(III) and similar subsections aren't needed, they could be summarized together. This actually requires a substainial contraction (consider a spin-off article called compounds of neptunium, like compounds of fluorine), I will write that later. Will say, though, that many salts (for example, hydroxides and oxides, and maybe they all) could be described together. Also, there's too much info on (for example) pnictides and carbides -- I would fit in no more that a single short to medium para. All of the example of compounds aren't needed here, instead the general trends is what you need.
 * Yup, I kinda based this a lot on the review of Yoshida et al., which is very comprehensive but also the kind of thing that is more for a subarticle instead.
 * Am kinda thinking that in the reduced and contracted section, I should still mention something about the oxidation states, because each state has a pretty distinct character for hydroxides/oxides. But you are right, the division is really IV/V/VI (more common) vs. III/VII (less common), and every element has that distinction. Double sharp (talk) 20:45, 9 August 2014 (UTC)

Precursor in plutonium production -- it's not clear if this is a real use or 237Np just happens to be an intermediate for a chain. It is clear, I mean, but the text doesn't make it clear.
 * ✅. It must be a real use: otherwise it'd be listed under some other element or isotope in sources. Double sharp (talk) 20:45, 9 August 2014 (UTC)

"small grains will ignite spontaneously in air at room temperature" -- give me an exact quote in the source
 * Hmm. There appears to have been a mistake made here: the source doesn't support this statement. I know I saw this in one of the sources, but the wrong source tag has been placed here. Double sharp (talk) 20:45, 9 August 2014 (UTC)

A nice article, I must say. It will require some work before FA, I think, but is good and has potential.--R8R (talk) 23:51, 8 August 2014 (UTC)
 * Thank you! Double sharp (talk) 20:45, 9 August 2014 (UTC)

The irony is even better
According to Plutonium: A History of the World's Most Dangerous Element (p. 45), some of those early workers on transuranic elements had observed a strange 23-minute half-life, but did not follow up on it. Of course, now we know that they missed 239U beta decaying to 239Np and 239Pu... Double sharp (talk) 16:35, 30 April 2017 (UTC)

External links modified (February 2018)
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Nuclear Weapons
Why is Neptunium unable to be used in fission bombs? Plutonium can, Uranium can, Neptunium is in the middle between them. So why can't (or isn't) it used in nuclear weapons? -An amateur researcher — Preceding unsigned comment added by 24.8.102.214 (talk) 21:48, 22 March 2013 (UTC)
 * The page specifically mentions that it is possible. See Neptunium. I have no idea why no one uses it. Reatlas  (talk) 01:39, 23 March 2013 (UTC)


 * This is just educated speculation. The Plutonium page says that the critical mass of that is 16kg and this can be reduced to 6.2kg by use of a tamper and the implosion method. The critical mass of Neptunium is given as 60kg. As both Plutonium and Neptunium have to be synthesized the fact that a lot more Neptunium would be needed is probably the reason that it not used for atomic weapons.


 * Uranium is naturally occurring and the fraction that is useful for atomic weapons can be extracted from this.


 * Less Plutonium is needed for an atomic weapon than one using Uranium. This enables the weapon to be smaller / lighter. For this reason (and maybe other technical matters) Plutonium is preferred to Uranium for atomic weapons. Similarly I think it is a matter of practicality that Neptunium is not used in atomic weapons.


 * FerdinandFrog (talk) 13:33, 4 February 2019 (UTC)

Information Sources
Some of the text in this entry was rewritten from Los Alamos National Laboratory - Neptunium. Additional text was taken directly from the Elements database 20001107 (via dict.org), Webster's Revised Unabridged Dictionary (1913) (via dict.org) and WordNet (r) 1.7 (via dict.org). Data for the table were obtained from the sources listed on the subject page and WikiProject Elements but was reformatted and converted into SI units. --

Density
The densities are written here as Mg/m^3. Isn't it more usual to use g/cm^3 ? Well, I guess it's a choice between physics and chemistry. Hmmm, did I just answer my own question?

Talk
What resource gave the name poseidonium? A Google search for poseidonium turns up only pages that come directly from this Wikipedia article or pages that mention the Poseidonium, a temple to Poseidon. -- Bkell 23:24, 23 Feb 2004 (UTC)


 * Hm. An anon added that some time ago. I removed it. --mav

Rarer than astatine?
Is it known if neptunium's natural occurrence rate is higher or lower than that of astatine (which is commonly claimed to be the "rarest naturally occurring element")? (See also Talk:Astatine where At is compared with Fr, Tc, Pm in this respect.) --Roentgenium111 (talk) 19:08, 20 July 2011 (UTC)
 * The berkelium article states that Bk is the rarest. Double sharp (talk) 08:22, 20 June 2012 (UTC)
 * Replying to myself just over seven years later: that was only from one source, Emsley's Nature's Building Blocks (2011), and we never found any corroborating studies, so we have removed that claim. On p. 423 Holleman & Wiberg give for the Earth's crust 45 mg At, 100 g Fr, 12 kg Pm, 25 kg Pu, 1.2 tons Np, 8.5 tons Rn, 2500 tons Po, 7000 tons Ac, so astatine is in fact rarer than Fr, Pm, Pu, and Np. Double sharp (talk) 14:55, 7 July 2019 (UTC)

Source
If anyone wonders, the information on weapons applications and planned supply relocations came from an Associated Press wire story. Bird 04:06, 2 Apr 2004 (UTC)

The U.S. Department of Energy declassified the fact that neptunium and plutonium-238 are fissile in 1998. -

β-Np space group problems
The article currently lists β-Np as "P42", following (Yoshida 2006 pp. 719 ). However, if you check the tetragonal space groups, no such space group exists. Following the reference back to a book by (Lemire 2001, pp.86 ) has P4212. On the other hand, (Mehl 2016 pp. 252 ) says that Pearson's handbook has "P421", but the correct space group is "P4/nmm" based on (Structure Reports v. 15, pp. 121, 1955).

I'm not sure if the correct group is P4212 or P4/nmm, but the current article is almost definitely wrong. $$\langle$$ Forbes72 &#124; Talk $$\rangle$$ 01:22, 12 June 2020 (UTC)
 * The experimental paper all the above sources are ultimately based on (Zachariasen 1952 ) which lists space group of β-Np as "P421", and gives the basis as:
 * 2 Np (I) in (0,0,0), (1/2, 1/2, 0)
 * 2 Np (II) in (1/2,0,u), (0,1/2,$\overline{u}$)
 * Where u=0.375 +/- 0.015. This reportedly matches the data reported by (Wyckoff "Crystal Structures" 1963 vol 1 pp. 47) which I don't have access to, so I can only verify indirectly, through Crystallography Online or American Mineralogist Structure Database. This has space group P4212 which (with some dispute) seems to be the space group with the most support in the literature. $$\langle$$ Forbes72 &#124; Talk $$\rangle$$ 06:36, 21 June 2020 (UTC)

Independent discovery
Also independently discovered by Kurt Starke (should be added). Double sharp (talk) 14:30, 13 September 2021 (UTC)
 * Or perhaps not independently after all? In any case, for neutrality I have simply added that in 1942, the Berlin researchers reported that they had found 93 as well. Double sharp (talk) 08:45, 14 September 2021 (UTC)