Wikipedia:Featured article candidates/Californium/archive1

Add links
From Wikipedia, the free encyclopedia
The following is an archived discussion of a featured article nomination. Please do not modify it. Subsequent comments should be made on the article's talk page or in Wikipedia talk:Featured article candidates. No further edits should be made to this page.

The article was not promoted by SandyGeorgia 19:34, 11 March 2011 [1].

Californium[edit]

Californium (edit | talk | history | protect | delete | links | watch | logs | views)

Toolbox
Nominator(s): mav (reviews needed) 22:33, 14 February 2011 (UTC)[reply]

I've been working on this article for some time now and think it now meets all FA criteria. If it is still weak in one or more areas, please tell me and I'll try to fix those issues. The article is already A class content-wise and has recently gone through a PR. This is an obscure element that is only available in tiny amounts, so it was difficult to find sources that had significant content that would be appropriate for a general encyclopedia article. mav (reviews needed) 22:33, 14 February 2011 (UTC)[reply]

  • Comment—I participated in the peer review of this article. It is in pretty good condition but the first three sub-sections are really thick with jargon. I gave it another read-through and found a few more issues I'd like to see addressed:
The third paragraph in ===Physical properties=== was the worst offender; it added content best suited for a table and concepts that are well beyond the interest or understanding of a general reader. So I removed it. I think the rest can be mostly understood in context by anybody who has taken and passed high school chemistry while preserving info useful to an expert. --mav (reviews needed) 01:59, 16 February 2011 (UTC)[reply]
It's looking better now. Thank you.—RJH (talk)
The jargon-filled compounds section has been moved to its own article. The section added little and was a bit of an aside anyway. Other edits made to help explain jargon in context and make prose more clear. --mav (reviews needed)
    • The lead does not cover most of the Characteristics section, nor the production or precautions sections.
    • Why does the physical properties section switch from Centigrade to Kelvin and then back to Centigrade?
      Centigrade is the de-facto standard temp scale used in chemistry for normal temperatures but extreme temps make more sense expressed in Kelvin. --mav (reviews needed) 01:06, 16 February 2011 (UTC)[reply]
    • What is the 'Cp' in Cp3Cf? The Cp article says only that it is an obsolete symbol for Lutetium and Copernicium.
      It is the symbol that represents a metallocene, which is C5H5-. But that is getting too much in the weeds, so removed. --mav (reviews needed) 01:13, 16 February 2011 (UTC)[reply]
    • I think this sentence needs a little work: "Its use in mineral prospecting and in medical treatments and research means it can be found near facilities that use californium." Is this trying to say that mishandling results in some loss of the element?
      Source does not say. Sentence changed to "Californium can be found near facilities that use the element in mineral prospecting and in medical treatments." --mav (reviews needed) 01:32, 16 February 2011 (UTC)[reply]
    • I don't think this statement is quite accurate: "Electromagnetic emissions possibly caused by the decay of californium-254 are observed in the spectra of some supernovas." The observation was that the characteristic light curve of a supernova explosion is very similar to energy curve emitted by the 55-day day half life of Californium. Hence it was suggested that supernovae generated large amounts of Californium, which supplied the energy for the light emission. However, this is now known to be incorrect since the energy comes from the decay of nickel-56. I don't believe the spectra of Californium was ever observed.
      Good catch. Commented out pending finding a good cite refuting the older work. Then maybe turn it into a footnote. --mav (reviews needed) 01:39, 16 February 2011 (UTC)[reply]
    • Could the article give an energy (in eV) of the neutrons emitted by californium-252? (Or a mean energy if it is emitted over a range?)
      Is this what you had in mind? --mav (reviews needed) 02:43, 17 February 2011 (UTC)[reply]
      • This source says that the fission neutrons have an energy range of 0 to 13 MeV with a mean value of 2.3(2–3?) MeV and a most probable value of 1 MeV (which I interpret to mean it has a heavily skewed energy distribution).—RJH (talk)
        • Cool, thanks. Added. --mav (reviews needed) 21:22, 20 February 2011 (UTC)[reply]
          • Unfortunately, I couldn't tell from the source whether it was 2.3 MeV or 2–3 MeV. The notation 2·3 MeV is unclear, which is why I wrote "2.3(2–3?) MeV". Thanks.—RJH (talk) 22:56, 23 February 2011 (UTC)[reply]
            • The paper uses 55•0% somewhere on the second page and throughout the text it keeps using this notation. I bet it's because of being a 50's article. So 2.3 looks correct. Nergaal (talk) 00:10, 24 February 2011 (UTC)[reply]
  • Thank you.—RJH (talk) 16:35, 15 February 2011 (UTC)[reply]
    • Thanks for taking another look; I will start to address each point once I get home from work. --mav (reviews needed) 19:39, 15 February 2011 (UTC)[reply]

Disambig/External Link check - no dabs or dead external links. 1 external redirect which may lead to link rot; see it with the tool in the upper right of this page. --PresN 00:40, 18 February 2011 (UTC)[reply]

Ah - HTTP 302. I missed that. Now fixed. --mav (reviews needed) 17:36, 20 February 2011 (UTC)[reply]

Source review

  • Coren's tool showed only a mirror. I've done a couple spotchecks and found nothing concerning, but don't have access to many of the sources
  • Cuningham or Cunningham? Inorganic and Nuclear Chemistry or Inorganic Nuclear Chemistry?
    Cunningham and and. Fixed. --mav (reviews needed)
  • Page number(s) for Seaborg 2004?
    Added. --mav (reviews needed) 20:52, 20 February 2011 (UTC)[reply]
  • Be consistent in whether publisher locations are included, and whether states/countries are included for locations. Also "Oxford, England, UK" is excessive
    Locations added for all books where given and available. State and country format made consistent except for world cities, where such disambiguation is unwelcome. --mav (reviews needed) 18:25, 20 February 2011 (UTC)[reply]
  • Use a consistent date format
    Done within each level of detail. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • Use a consistent format for sources with multiple authors
    Done. --mav (reviews needed)
  • Be consistent on when you use et al - I see a four-author work that uses it and an eight-author work that does not
    Et al. now used after the third author except in cases of four authors. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • I would advocate for spelling out journal names on all occurrences. Acronyms like "CRC" should also be spelled out or linked
    Good idea. Done. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • Check formatting for ref 49 (Seaborg 1994)
    Converted to cite book. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • Ref 43 should be identified as a PDF
    format=PDF added. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • Be consistent in what is wikilinked when in references
    All journal names and publishers linked. --mav (reviews needed) 20:25, 20 February 2011 (UTC)[reply]
  • "in airport neutron-activation detectors of explosives" - source?
    Not in my cites or on Google Books, so commented out. --mav (reviews needed) 20:52, 20 February 2011 (UTC)[reply]
  • Be consistent in how editors are notated
    Errant "(editor) removed. Everything else is per cite template format. --mav (reviews needed) 20:52, 20 February 2011 (UTC)[reply]

Sources seem reliable, although I can't speak to comprehensiveness. One question, though: you seem to use a considerable number of older sources and a few tertiary sources. Is there a reason for this?

Much of the work on this element occurred in the 1950s and 1960s. Most of the specialized encyclopedias used summarize primary sources and thus are secondary sources. The others are used sparingly. --mav (reviews needed) 20:52, 20 February 2011 (UTC)[reply]

Nikkimaria (talk) 15:00, 18 February 2011 (UTC)[reply]

Thanks for the review. I'll address each point this weekend. --mav (reviews needed) 03:23, 19 February 2011 (UTC)[reply]

There are some areas that seem to awkwardly mix phrasings and/or tenses. Here's one where a better phrasing would drastically improve clarity:

  • "Two to six out of 100,000 people are estimated to die of a fatal cancer if they were continuously exposed to soil with an initial average concentration of 1 pCi/g of californium-251 and californium-249, respectively."

The "are" followed by "if they were" is rather disconcerting. {{Nihiltres|talk|edits|⚡}} 16:12, 18 February 2011 (UTC)[reply]

Thanks for the review. I'll address each point this weekend. --mav (reviews needed) 03:23, 19 February 2011 (UTC)[reply]
Hm. I'm not sure if this addresses your exact concern but I revised the sentence to hopefully make it more understandable: "An incidence of two to six fatal cancers are expected to occur for every 100,000 people continuously exposed to soil with an initial average concentration of 1 pCi/g of californium-251 and californium-249, respectively." I'll keep your general comment in mind as I copyedit. --mav (reviews needed) 21:32, 20 February 2011 (UTC)[reply]
More jargon moved to daughter articles or explained/made more clear. --mav (reviews needed) 03:31, 28 February 2011 (UTC)[reply]
  • Missing bibcodes: would be good to add bibcodes to journal cites where available e.g. Bibcode:1956PhRv..102..180F is one. Also use of {{LCCN}} template would be useful to link reader to record (still within |id=). Rjwilmsi 23:15, 21 February 2011 (UTC)[reply]
  • Is there any indication that Cf is the heaviest element isolated in elemental form? If that was the case, then it would be worth mentioning it somewhere. Nergaal (talk) 03:17, 22 February 2011 (UTC)[reply]
    No. Our articles say its fermium, but I think its dubious too - we need a criterion of how many atoms make a solid (or element, or what is "visible", "weighable", etc.) and then compare it with numbers produced. Materialscientist (talk) 03:36, 22 February 2011 (UTC)[reply]

Comments after doing a few edits:

  • bulk modulus of 50 GPa: how does this compare to other more common materials (so a layperson can appreciate the value)?
    Added Al for comparison. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • "hydrogen hydrides" what is that? (the word hydrogen is probably wrong)
    Removed. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • "Californium(IV) oxide (CfO2) is formed by oxidation at high pressure. " high pressure of air or O2? and how high? 10 bars, or 10kbars?
    • MS: why did you delete this?
      Removed - in the original article the authors used high gas pressure (bars I guess) to speed up the natural oxidation process without the need for high temperatures, but they didn't have to. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • " Fission neutrons of californium-252 have an energy range of 0 to 13 MeV with a mean value of 2.3(2–3?) MeV and a most probable value of 1 MeV.[25]" while interesting, very few readers whould get anything out of this without further details. What is 3? supposed to mean? How much is 1 MeV for a fission neutron? I am tempted to suggest moving half of this info to a footnote.
    It was 2.3 with middot coming from an old notation for the decimal separator. To clarify why the energies are so different - 1 is sum average and 2.3 is statistical fit. I am puzzled by how to answer on "How much is 1 MeV for a fission neutron" - it is a lot for a neutron (can knock any atom from any solid), but might be low or high for different fusion reactions. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • "Californium metal was first prepared in 1974" what scale did they get? miligrams? less? picturable?
    Clarified. They deposited small-area thin films suitable for electron microscopy, i.e. they did not have to maximize the amount. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • is there an estimate on the total amounts of the element synthesized until now? more than 10kg?
    It should certainly be less than 100 g.Materialscientist (talk) 04:23, 24 February 2011 (UTC)[reply]
  • "very minute amounts might exist in some uranium ores" from the uranic neutrons?
    "Clarified". I guess not only neutrons, but also other reactions (alphas). Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • " Compounds containing ... but pure samples of the metal have not been made in particle accelerators." not sure if this sentence sounds right
    It was indeed odd. Fixed. I guess it meant to say that pure metal is produced in accelerators and compounds in reactors, which is somewhat dubious - it is always produced as a metal, but converts to compounds (by surface reactions) later. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • "Californium isotopes with mass numbers 249, 252, 253, and 254 were observed for the first time in the radioactive dust collected from the air after an explosion.[44]" I would say this should be moved to the history section with the reference to 1956
    Well, it is talking about how Cf gets into the environment. Thus I think it is best to keep it in the occurrence section. As I say below, this is a synthetic element so all aspects of its occurrence will be tied to history in some way. --mav (reviews needed) 02:23, 28 February 2011 (UTC)[reply]
  • should the occurrence section be part of the characteristics one?
    Mav can add more, but for most elements "occurrence" is much closer to "production" and thus placed there, as a separate section. Materialscientist (talk) 04:23, 24 February 2011 (UTC)[reply]
    Given this is a synthetic element, I agree; occurrence in the case of Cf is directly related to human production. But occurrence does make more sense placed in the characteristics section for some elements, such as oxygen, where occurrence naturally flows from a stellar nucleosynthesis-oriented isotopes section. --mav (reviews needed) 02:23, 28 February 2011 (UTC)[reply]
  • rename production to nucleosynthesis?
    "Production" is the standard WP:ELEM section title and is more accessible than nucleosynthesis. --mav (reviews needed) 02:23, 28 February 2011 (UTC)[reply]
  • "4997Bk(n,y)25097Bk" I would use a non-shorthand notation for this reaction (what is "y" here?)
    Its γ. Fixed. Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • "Californium in the skeleton adheres to bone surfaces before slowly migrating throughout the bone." needs citation
    Verified and moved the supporting citation (it was oddly placed). Materialscientist (talk) 00:32, 24 February 2011 (UTC)[reply]
  • maybe mention how much Cf was used/given to discover Uuo
    Added from the source. The Russian team used about 10 mg in their both attempts. Materialscientist (talk) 04:23, 24 February 2011 (UTC)[reply]

As expected from Mav, a very nice article! Nergaal (talk) 20:16, 23 February 2011 (UTC)[reply]

Thank you all for your comments on and edits to the article. I've been out of town for the last couple days and just got back. I'll start to address concerns later on Friday and during this weekend. --mav (reviews needed) 10:35, 25 February 2011 (UTC)[reply]

  • It looks like some things are missing. I have just noticed that californium is the heaviest element that has been reported in supernovae from the nucleosynthesis page lead section, but that fact has the [citation needed] tag next to it. I would have included it if only that tag was not there, but it is and thus I cannot put it in. Can somebody find the natural californium source page? There seem to be a few other details that need putting in. I want the article to become featured, and so I need all the help of my fellow Project Elements users - Lanthanum-138, Mav, Nergaal, and a few others. Let's do this together. (Mav, can you help me?) FREYWA 06:18, 4 March 2011 (UTC)[reply]
This is discussed on the talk page under Not in supernovae (I presume). The claim goes back to 1956 and is outdated by later observations.--Stone (talk) 00:01, 5 March 2011 (UTC)[reply]
Ref note added about supernovae. This element seems to be a magnet for incorrect initial findings or counter-findings that keep getting repeated in otherwise reliable sources (it took me over a month to resolve whether metallic Cf had been prepared or not). Wikipedia is a great place to work these issues out. Please feel free to copy and/or modify my note to other articles. What other details are missing? I intentionally overlooked a lot of really technical info that is well beyond the interest or understanding of a general encyclopedia reader. --mav (reviews needed) 14:18, 5 March 2011 (UTC)[reply]

Comments

Lead
  • Is "weighable" a word? And shouldn't the technical and scientific term be "mass"?
  • I've seen it used several times in technical literature, but changed to "amounts large enough to see with the unaided eye" instead. --mav (reviews needed) 18:48, 6 March 2011 (UTC)[reply]
    • I looked it up, and it is a word, but your change addresses the concern anyway (no comment on what should, ultimately, be used in these synthetic element articles). Carcharoth (talk) 19:37, 6 March 2011 (UTC)[reply]
  • "is one of highest atomic mass elements" - missing word 'the' (surprised this was missed in copyediting).
    Fixed. --mav (reviews needed) 18:48, 6 March 2011 (UTC)[reply]
  • "is one of highest atomic mass elements" - possibly a hyphen is needed somewhere as well.
    I don't think so... --mav (reviews needed) 18:48, 6 March 2011 (UTC)[reply]
    Er, yeah. I need to think twice before suggesting hyphens. Carcharoth (talk) 19:37, 6 March 2011 (UTC)[reply]
  • "Californium slowly tarnishes in air at room temperature and disrupts the body's ability to form red blood cells by bio-accumulating in skeletal tissue." - These two separate properties shouldn't really be conflated in a single sentence. It is jarring to have to mentally switch from a picture of a tarnishing metal to californium-poisoning. i.e. If read too quickly, the reader will think that one property follows on from the other. Suggest splitting into two sentence or rephrasing.
    Separate sentences now. --mav (reviews needed) 18:48, 6 March 2011 (UTC)[reply]
Characteristics
  • "Weighable amounts of californium make it possible to determine some of its properties" - again with the word weighable. But I think the point here is that you have sufficient quantities of the elements to determine certain properties. i.e. it is not the fact that it is weighable, but that you have enough of it to do certain things (including weighing it). The whole section would read better if you just said "As a synthetic element, the properties of Californium can only be determined if enough of it is produced and the isotopes produced are stable enough to be analysed". On the other hand, if "weighable" is a technical term specific to studies of chemical elements, and synthetic elements in particular, then a footnote to that effect will help.
    Changed to "Unlike many other elements heavier than plutonium, enough californium can be collected to determine some of its properties." --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
  • It is not immediately clear to me that α and β are the Greek letters alpha and beta. I usually like to see some parenthetical note telling me what the symbol is, if it can be described simply.
    fixed. --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
  • If the "double-hexagonal close-packed form" exists below 900 degrees C, does the "face-centered cubic form" exist above 900 degrees C? The lead seems to imply this, with "two crystalline forms under normal pressure, one above 900 °C and one below", but the section here in the main body of the article seems to have missed out the words "that exists above 900 °C" for the β form.
    Correct, clarified. --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
  • Note 1: "The three lower mass transplutonium elements require much less pressure to delocalize their 5f electrons" - would it be possible to name and link to these other three elements? Also, lower-mass needs to be hyphenated.
    americium, curium, and berkelium mentioned and linked in note. --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
    I've passed on the hyphen bit... Carcharoth (talk) 19:37, 6 March 2011 (UTC)[reply]
  • Why is the bulk modulus compared to that of aluminium? A random comparison or a standard one?
    There is no standard comparison for this value. Aluminium is chosen as an element, which is accessible to most readers and which has a value close to that of Cf. Materialscientist (talk) 06:50, 6 March 2011 (UTC)[reply]
    What MS said. I made this clear in the text via "... but smaller than more familiar metals, such as aluminium ..." --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
    Thanks, that makes it much clearer. Carcharoth (talk) 19:37, 6 March 2011 (UTC)[reply]
  • "similar to other 3+ actinide elements" - not everyone will realise "3+" refers to valence here. Suggest rewording to "similar to other 3+ valence actinide elements".
    Done. --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
  • "and dysprosium, which is the lanthanide above californium" - suggest using the word "element" before dysprosium to make things clearer.
    Done. --mav (reviews needed) 19:18, 6 March 2011 (UTC)[reply]
  • "chalcogen" - this one threw me, and I'm moderately familiar with most chemical terms. Suggest explaining what a chalcogen is, as it doesn't take long.
    It might sound odd, but "chalcogen" is less ambiguous than its explanation "an element of group 16" - whereas "chalcogen" is a very common term, group 16 is confused with group 6 (VI) even by scientists :) (because of coexistence of the wide/compact periodic tables). No slightest disrespect to this comment, but basic notions are to be wikilinked rather than explained. Materialscientist (talk) 06:50, 6 March 2011 (UTC)[reply]
    OK, but since oxygen is a chalcogen, is there not redundancy or imprecision in saying "hydrogen, nitrogen, oxygen or a chalcogen"? I tried rephrasing it, but it is difficult. Carcharoth (talk) 07:32, 6 March 2011 (UTC)[reply]
    Sure, oxygen is chalcogen. Needs a prose tweak. Materialscientist (talk) 07:48, 6 March 2011 (UTC)[reply]
    Rephrased to "a chalcogen (oxygen family element)" --mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
  • If it reacts with hydrogen when heated, why is the reaction with "dry hydrogen" rapid? This seems like a discrepancy without further explanation.
    I presume small amount of moisture will modify (oxidize) the surface of Cf and slow down the reaction. Many reactions stop by such surface layer, whereas pure dry hydrogen easily diffuses through and reacts with the bulk of a metal. Materialscientist (talk) 07:48, 6 March 2011 (UTC)[reply]
  • What are the products of the reactions named in this section?
  • "Few californium compounds have been made and studied." - is it possible to have a rough range here? Less than ten? Less than 20?
  • It is not clear here how you get from the samples of californium, freshly produced by the methods described later in the article, to the oxidation states being described here. When it tarnishes in air, for example, which oxide is produced? Ditto for all the other compounds named - how are they produced?
  • Is there a reason the 'Chemical properties and compounds' section uses "further information" and the 'Isotopes' section uses "main article"?
    Because Compounds of californium is not supposed to be strictly an expansion of the chemistry and compounds section in this article; instead, the daughter article expands on just one part of the subsection here. Yet, that is the case for Isotopes of californium. --mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
    OK, though I've seen "see also" used at the top of sections. I've only rarely seen templates like that used at the end of sections. It just looks strange to me. I see no reason not to put all such "see other bit over here" pointers at the top of sections. i.e. my objection (and I wasn't clear on this) was more about the placement of the pointer template. I'm so used to seeing them at the top of sections that seeing one at the bottom of a section is jarring. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • "The isotopes of californium range in mass number from 237 to 256." - would it be possible to have a source for this?
    Same as the rest of the paragraph. Added anyway. --mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
  • "due to its high neutron capture and fission cross section" - it shouldn't be too hard to put this in a less technical way - my understanding of that is that it is unstable in the environment it is formed in (the earlier mentioned "intense neutron radiation in a nuclear reactor"), due to being split up by neutrons that hit it soon after it is formed (quite why this is the case for this isotope and not others is another question, which would require unpacking the mechanics of nuclear reactions a bit more).
    Changed to "...due to its propensity to collect neutrons (high neutron capture) and tendency to interact with other particles (high cross section)."--mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
  • You describe the decay products of Californium-252, but not of the other isotopes. What do Californium-249 and Californium-251 decay into? Isotopes of californium was no help here.
    Already mentioned in the Most stable isotopes part of the infobox. Cf-252 is the most important isotope so it is also mentioned in the prose. We normally summarize trends here by stating what the most common decay modes above and below the longest lived isotope are but there is no such trend for Cf. The best I can do is add: "Most of the other isotopes of californium decay to isotopes of curium ( Z = 96) via alpha decay."--mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
    I forgot to look in the infobox. As I said, I went looking in Isotopes of californium and that didn't give the decay products apart from a very small entry in {{Actinidesvsfissionproducts}} for Cf-250 to Cm-243 (I had to look hard at that template to find that), so I assumed no-one had listed them anywhere yet. It seems strange that the infobox for the element would be more detailed than the article on the element's isotopes, but maybe that just indicates more work is needed on the related articles. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • "Californium-252 undergoes α-decay" - the term "alpha decay" is not linked here, and is written using the Greek letter. Later on in the article, the term is linked, and written as "alpha decay". Earlier in the 'Isotopes' section you link beta decay. Inconsistent linking and use of α/alpha and β/beta. Suggest whole article is checked for this.
    Fixed in this section. --mav (reviews needed) 20:07, 6 March 2011 (UTC)[reply]
    Looks OK elsewhere as well. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • "One microgram spontaneously emits 2.3 million neutrons per second." - you link to microgram. Interesting as that article is, I'd much rather learn whether 2.3 million neutrons per second is a lot or not (it sounds like a lot). Also, is the energy range given for its neutrons high, low, or normal? i.e. Can the harmfulness of Californium-252 be compared to other radioactive isotopes. I realise it is not possible to do this if the sources don't say anything, but these are obvious questions readers will ask themselves.
History
  • Your NYT source says ""Element Created; Has Heaviest Atom" - but the Wikipedia article is silent on what this means. Can this be clarified?
    The NYT is hardly a good thing to cite here anyway; it is simply cited to back up an inane statement about Cf not having a known use or value when it was discovered. As if knowing what the use or value of a newly discovered element was expected by anybody who had a clue about how basic science works; one normally has to perform lots of tests before finding out what use a new element may have. Cite and statement removed. --mav (reviews needed) 20:42, 6 March 2011 (UTC)[reply]
  • "35 MeV alpha particles" - I think this should be hyphenated as "35-MeV alpha particles" (as opposed to 35 particles of a MeV each).
    Good idea. Done. --mav (reviews needed) 20:42, 6 March 2011 (UTC)[reply]
  • Note 2: "set-aside" - this shouldn't be hyphenated here. The "difficult to get to California" bit is cute.
    Fixed and yep. :) --mav (reviews needed)
  • "Californium metal was first prepared in 1974" - this begs the question of what state the 5000 atoms initially produced in 1950 were in. Is this "unknown", or were they ions detected by the synchrotron? You also say that "nuclei" were produced in 1950, and then later say "atoms". Which was it? Nuclei or atoms?
    Certainly atoms. Those 5000 atoms were scattered in the target composed of another material (which turned into a complex mixture after irradiation) and were detected by energy and character of emitted particles. I believe those were individual atoms (per low conversion probability) in a solid matrix, and that there was no technique to ascertain that in the 1950s (even now such identification would not be trivial). Materialscientist (talk) 07:03, 6 March 2011 (UTC)[reply]
    Thanks, that makes it clearer. So should the one instance of "nuclei" be changed to "atoms"? Search for "nuclei" in the text of the article. I suppose the equations are for nuclei, aren't they? Though if the beta particle is shown with a minus sign, why is the alpha particle not shown as a double positive charge? Alpha decay has a 2+ by the helium nucleus. I know the electrons matter little here, as these are nuclear reactions, not chemical reactions, but it still seems inconsistent. Carcharoth (talk) 07:55, 6 March 2011 (UTC)[reply]
  • "long-duration irradiation" - what duration? Is this days, months, years? (You do give a hint later, with the "five years" bit).
  • You fail to give the year for the weighable quantities bit.
    The actual journal article that published the achievement is cited. I don't have access to that article, so I can't say if the achievement was done the same year as publication or before that (or even if the article mentions the date). --mav (reviews needed) 20:42, 6 March 2011 (UTC)[reply]
    I would suggest either trying to get hold of a copy of the reference, or giving the year the results were published. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • Why is the metal production year (1974) put in so early? It seems out of order with the rest of the history.
    An artifact of section expansion. Fixed. --mav (reviews needed) 20:42, 6 March 2011 (UTC)[reply]
Production
  • "Bombardment of californium-250 with neutrons produces californium-251 and 252" - you need to either pre-hyphenate 252 or write out californium a third time, or rephrase this.
    Done. --mav (reviews needed)
  • "Millionth gram" - this needs hyphenating, but isn't this just another way to say "microgram"?
    Changed to "microgram" --mav (reviews needed) 21:03, 6 March 2011 (UTC)[reply]
  • "Only two sites produce californium-252" - this repeats what was said in the 'History' section. Readers will notice this. But in any case, the material in each section looks at first glance to be contradictory! The history section says "The High Flux Isotope Reactor (HFIR) at the Savannah River Site in South Carolina" and the rest of the article (including the production section) says "Oak Ridge National Laboratory". When you click on High Flux Isotope Reactor you find out it is "located at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee". But then you go back to the history section of this article, and find that it says "at the Savannah River Site in South Carolina". What is going on here? (Note that the 'Applications' section mentions the 'Savannah River Plant' as well.) The quantities mentioned in the two sections don't seem to match up either. I would say, work out what needs saying, and say it in one section only. Note also my comment on the talk page of this FAC page about the IP edit that seems to have caused the confusion here.
    Argh - History section cleaned-up. I need to recheck all relevant sources to clear this up in all affected sections. --mav (reviews needed) 03:10, 7 March 2011 (UTC)[reply]
  • "available for commercial use through the U.S. Nuclear Regulatory Commission" - here, it is worth making clear that the regulatory activities passed to this body (give the year) from the Atomic Energy Commission mentioned in the History section.
  • You gave a price in the history section. Are no current prices available?
    For such elements the price is rarely available in reliable sources, and I can only speculate why (e.g. all orders are highly individual, they specify the required purity, form, etc., that affects the price). Materialscientist (talk) 07:26, 6 March 2011 (UTC)[reply]
    Fair enough. An example here would at least give some idea, but it may be best to let readers look this one up themselves if they are curious. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • "Three californium isotopes with significant half-lives are produced, requiring a total of 14 neutron captures by uranium-238 without nuclear fission or alpha decay occurring during the process." - For this sentence to really sink in, it would be best to point out that the berkelium (and the elements it is produced from) are all themselves made in nuclear reactors or particle accelerators, in a chain that can be traced back to uranium (as in the diagram). This point hasn't been made earlier in the article.
    Good idea. Added "Californium-253 is at the end of a decay chain that starts with uranium-238, includes several isotopes of plutonium, americium, curium, and berkelium and the californium isotopes 249 to 253 (see diagram)." --mav (reviews needed) 21:03, 6 March 2011 (UTC)[reply]
Applications
  • "half-lifes" - should this be "half-lives"?
  • "received a loan of 119 µg of californium-252" - do you need to link or write out "µg"?
    Note to Mav: it stood as mg, but changed to µg a few hours ago per source
    See also my note further down about µg vs mg vs g. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • "Neutron penetration into materials makes it useful" - replace "it" with "californium".
  • As an aside, the 'applications' section is very interesting and well-written, and the changes in use over time was fascinating (the californium bullet bit was hilarious - though not really an 'application' is it?).
  • "and fission fragment and half-life studies are other applications of californium" - by "fission fragment" do you mean "fission fragment studies"? I found this sentence a bit impenetrable. It would be nice to know what fission fragment studies are and how californium is used in half-life studies.
    To clarify: "studies of fission fragments [chemical identity] and half-lives". Technically, these might be different measurements, of emission energy, emitting particle nature, and of decay time. Materialscientist (talk) 07:37, 6 March 2011 (UTC)[reply]
Precautions
  • "an initial average concentration of 1 pCi/g" - any chance of explaining what this means? Comparing it to something else? Is this, for example, considered a safe or dangerous level? How does it compare to the levels mentioned in the 'Occurrence' section?
Other
  • Didn't check the infobox (I saw some verification thing going on in all the chemical infoboxes, that I assume has been done now?), though it does look fascinating, but the redlink "d" is a bit distracting. Minor quibble, I know!
  • Seaborg died in 1999. It confuses me to see "Seaborg 2004" in the references! Is there not a more elegant way to cite an entry in an edition that was published after the author of that piece died?
    It is the 5th edition, of an encyclopedia, which usually reprints former editions with minor additions and corrections. Materialscientist (talk) 07:37, 6 March 2011 (UTC)[reply]
    An extreme example of the same issue is for Mark Twain's autobiography (2010). The date is simply a publication date. I'm not aware of any citation convention that accounts for this type of thing. --mav (reviews needed) 18:25, 6 March 2011 (UTC)[reply]
    I'm going to strike this, as difficult to action or unactionable. Personally I'd not bother with giving the author here, as it is the encyclopedia editors that are taking responsibility for the republication of Seaborg's original entry. Out of interest, does the entry in that edition directly credit Seaborg or indicate when the entry was first written, and does it indicate whether updates have been made and does it credit any changes (the actual text of the entry might make it clear that changes have been made since the last edition)? FWIW, the first edition seems to have been 1994. Carcharoth (talk) 19:53, 6 March 2011 (UTC)[reply]
  • In the two equations in the article, I was able to understand what the equations were showing because I can read such equations, but someone with no science background would not recognise them. Is it possible to have links or words under each bit to explain them? In particular, something saying that Cm is curium, that He is (in this case) an alpha particle/helium nucleus, that Cf is californium (in case the reader has forgotten this), and that n is the symbol for a neutron? For the second equation, saying that Bk is Berkelium, that β- is a beta particle/electron, and that n,γ is (I think) neutron and gamma rays?
  • The article would read better, IMO, if it ended on the final sentence of the "applications" section. Has the order of sections in the elements articles been determined by WikiProject Chemistry? If so, fair enough, but the "Precautions" section ends on a fairly damp squib of a rather technical nature. Best of all would be to end with the "ununoctium" bit, sticking the "other applications of californium" sentence somewhere else.
    The section order is set by WP:ELEMENTS. See Wikipedia:WikiProject Elements/Guidelines. --mav (reviews needed) 18:33, 6 March 2011 (UTC)[reply]
    Though I see you don't stick rigidly to that layout, so technically this is actionable, or to put it another way, if I pointed out that parts of this article's layout don't conform to that WikiProject guideline (I'm not going to do this, as I agree with the changes you made), you would have to justify the changes, but it doesn't work the other way round? It's not a major concern, but it still stands, as I think ending an article on "precautions" is failing to consider the best way to finish the article. I'll have a look at some other featured articles on elements and consider this some more. Carcharoth (talk) 19:18, 6 March 2011 (UTC)[reply]
  • Seaborg's Nobel Prize was for his work on discoveries in the transuranic elements. I believe that that includes his work on this element. If that can be double-checked, it is worth mentioning here, I think.
    Nobel cite says "for their discoveries in the chemistry of the transuranium elements". Cf was announced in Feb. 1950 and the prize given in 1951. The speech mentions Cf, but as a recent addition, thus per my WP:OR I would say it was probably not a decisive element of the Nobel Prize award. Materialscientist (talk) 07:26, 6 March 2011 (UTC)[reply]
    That is the "Presentation Speech by Professor A. Westgren, Chairman of the Nobel Committee for Chemistry of the Royal Swedish Academy of Sciences". Now that you've pointed me there, I got to wondering what Seaborg sent in his Banquet Speech (unfortunately he gave it in Swediah and I can't understand it) or even in his official Nobel Lacture. I tried to find a suitable quote from there, but it doesn't really fit. There might be possibly pointers there to improve the history section still further, though. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • Two of the researchers mentioned in the history section either don't have articles or are wrongly linked here. Stanley Thompson (1893-1953) was a Canadian golf course architect. Kenneth Street (1890-1972) was an Australian jurist. I don't know if either were related to the researchers in question here, but it is kind of depressing that articles arrive at FAC without people at earlier review stages having checked links like this (please don't take offense at this, it is not directed at this article in particular - it happens on other articles as well). When I noticed this on another FAC article recently, I suggested that all the links be double-checked to make sure they go to the correct destination. It takes time, but is worth doing.
    Fixed by Stone and noted for future copyedits. --mav (reviews needed) 18:33, 6 March 2011 (UTC)[reply]
    I see Stone has created Stanley Gerald Thompson. And from there I found this (Stone had found a mirror site, I think, not sure about how that works), which is fascinating and a potential help in finding journal articles about the history of the discovery, but that could be a whole other article in itself. Carcharoth (talk) 19:10, 6 March 2011 (UTC)[reply]
    Additional note: I did short stub for Kenneth Street, Jr. as well. Street died in 2006. I wasn't aware that Ghiorso died only a few months ago (December 2010). A nice bit of trivia (not for this article) is that there was a proposal to give ununoctium the name Ghiorsium. Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]
  • The picture of the shipping cask is a great one for this article, but I was hoping to read something in the article about the technology involved there, and what the methods used are to transport this element and why such large and heavy casks are needed. I have a vague idea why, but I'm not going to speculate. The other question would be how the element is got out of that flask and into the equipment mentioned in the applications section.
  • In some places the article talks about milligrams, in others it talks about micrograms, and in others it talks about grams. This is a difference of several orders of magnitude. I noticed Materialscientist corrected at least one instance where microgram had wrongly been written as milligram. Is it possible to do a complete check through the whole article to make sure no similar mistakes are present? Carcharoth (talk) 03:25, 7 March 2011 (UTC)[reply]

Hopefully some of those comments will be of use. I'll check back over the next few days and see if anything else comes up on a second reading. Carcharoth (talk) 05:47, 6 March 2011 (UTC)[reply]

Thank you for the review - I'll start addressing your points later on Sunday. --mav (reviews needed) 06:36, 6 March 2011 (UTC)[reply]
  • Comments - reading through now - will make straightforward copyedits as I go (please revert if I inadvertently change the meaning), and jot queries below: Casliber (talk · contribs) 07:11, 11 March 2011 (UTC)[reply]
  • In the Physical properties section, you change from Celsius to Kelvin. I think it'd be better to stick to one or used C (K) or something.
Unresolved items copied to talk:Californium. --mav (reviews needed) 11:02, 12 March 2011 (UTC)[reply]


The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Wikipedia:Featured_article_candidates/Californium/archive1&oldid=1138456936"