Wikipedia:Featured article candidates/Atom

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 promoted 00:05, 18 February 2008.

---

Atom

Check external links

Self-nomination. This vital article has been through an extensive expansion, editing and review process, so I believe it is ready to become an FA candidate. It is a lengthy article as the subject is broad and some of the concepts needed a careful explanation. (The topics raised during the article reviews also resulted in article expansion, as did the need for comprehensiveness.) Hopefully this article is reasonably accessible to the educated non-expert.

Most of the article treats atoms as individual particles, but there is some material about bulk properties. For the latter, however, it primarily relies on the main article links to fill in the details. (In some cases those articles are in need of more development, but I'll leave that for a later date.)

Please take a look and see if you believe this article satisfies the FA criteria. I'll attempt to address specific concerns, where they make sense. Thank you.—RJH (talk) 18:25, 12 February 2008 (UTC)

Support I have had this article on my watchlist for some months meaning to improve it. I never got around to it, but observed it being greatly improved. This is also a Core topic. Zginder ^{(talk) (Contrib)} 20:28, 12 February 2008 (UTC)

• Support I see no reason to oppose. The writing is good, and it is very well sourced. Juliancolton (Talk) 13:27, 13 February 2008 (UTC)

• Support, great article, but please take care of a few things:

• "cooled to very low temperatures" in History section--how low? Be more specific than "very".
  • I added an approximate value.
• Same as above with "although this can require very high energies" in section Nucleus. "Very" isn't a useful word; better to be specific.
  • I gave a specific example of the minimum energy needed for fusion at the Sun's core (a couple of lines down). The amount varies by isotope, so I can't give a single value there.
• Confirm that anti-electron has a hyphen but antiproton doesn't.
  • The hyphen was removed.
• Get someone to copyedit the whole article... I found a few significant grammatical errors, but can't keep looking for more.
  • It's been over several times by different people. Thanks for the catches. If anybody else would like to do a copyedit review, that would be appreciated.—RJH (talk) 23:27, 13 February 2008 (UTC)

Overall, nice job! --Spangineer^ws (háblame) 19:46, 13 February 2008 (UTC)

• Comments: Just a very few comments; once those are addressed, I'll support - article looks very good and well-referenced, all in all.

• "Meanwhile, physicist Niels Bohr in 1913 revised Rutherford's model by incorporating the principles of quantum mechanics." - sounds a bit misleading, as, at that time, what we now call quantum mechanics hadn't really been formulated.
  • Revised.
• Quite generally, the history section reads as if describing atoms was more or less an application of quantum mechanics. What about the crucial roles that atoms played in the development of quantum theory? How come no mention of spectral lines in the history section?
  • It is a summary style section, so unfortunately I can't include everything. I agree that they are important topics, but perhaps it is satisfactory if they are covered on the linked main article page?
    • No question, summarizing is in order. But you're including so many details about quantum mechanics that it's odd there isn't a, well, summary statement about the overall role of quantum mechanics. And why equally important details (spectral lines) are left out. By all means, summarize at a higher level than you're doing at the moment.
      • Alas, the current bulk is partly the result of the PR process. I'm a little unsatisfied that is has become so lengthy. Perhaps the entire section should just be merged into the main article and only a link left behind?—RJH (talk) 15:53, 15 February 2008 (UTC)
• Where's kinetic gas theory? Or the statement that the key element that led to the general acceptance of the reality of atoms was the convergence of all the different ways to derive Avogadro's number?
  • The article has a low focus on bulk properties of atoms as they are covered in detail elsewhere. There is nothing in the Avogadro constant article about your statement, but it sounds like it may be worth mentioning.
    • I came across this during the Einstein year, in discussions of Einstein's contributions to the acceptance of the reality of atoms. Sounds to me like an important aspect, but at least brief googling hasn't brought forth any ready references. Sorry.
• "The component particles of an atom consist of" - awkward, when talking about composition. How about "The constituent particles of an atom are"?
  • Done.
• Binding energy and mass-energy: This paragraph looks a little disorganized - first the mass deficite, then the binding energy, and only later the mass-energy-equivalence needed to understand why the first two are related in the first place.
  • Re-org'd. —Preceding unsigned comment added by RJHall (talk • contribs) 16:16, 14 February 2008 (UTC)
    • Sorry to be picky, but wouldn't it make more sense the other way around? Binding energy first (that's where this comes from - interaction), then the fact that it's equivalent to a mass difference.
      • So you essentially want to say... once the nucleus has fused, it would require energy to pull it apart—the binding energy. This energy was emitted during the fusion process and it was converted from a change in mass, per Einstein. The is because the combined mass of the individual components is greater than the mass of the nucleus. Sorry but the direction of this explanation seems awkward to me.—RJH (talk)
• "Each atomic orbital corresponds to a particular energy level of the electron." - well, yes and no. As far as I can see, given the length of the article, something like the difference between quantum-number energy levels and fine structure should at least be mentioned, even if they are not explained in detail. Otherwise, someone looking at the image showing the different orbitals might just come to the false conclusion that each corresponds to a different energy quantum number.
  • I added a couple of sentences about fine structure.
    • I think it would also be good to address this (at least implicitly) in the "Electron cloud" section.
      • What would that add, besides redundancy?—RJH (talk) 16:06, 15 February 2008 (UTC)
• "The number of electrons in an atom can easily change. This is because the amount of energy needed to add or remove an electron (the electron binding energy) is far less than the binding energy of nucleons." - does this make sense? Couldn't there be a world in which chemical binding energies are much less than nuclear binding energies, but still higher than your typical photon energy or, equivalently, typical energy scales (temperature), so that nobody would ever get the idea of describing ionization as "easy"? The comparison shows why it's easier, not why it's easy.
  • I replaced the first sentence with an example (following the second sentence).—RJH (talk) —Preceding comment was added at 21:23, 14 February 2008 (UTC)
• "Any two atoms with an identical number of protons in their nuclei will be the same chemical element. Atoms with the same number of protons but a different number of neutrons will be different isotopes of the same element." - I think it should be made clearer that this isn't some physical insight, but a matter of definition: "Any two atoms...represent the same chemical element. Atoms with... are called different isotopes of the same element."
  • I added "by definition", although it seemd clear already. =)
• "mass of an atom at rest" - since a number of readers will wonder why "at rest" is important, please wikify.
  • Done.
    • Oops, my bad - I meant that there should be a wiki-link to rest mass (which, as I see, re-directs to invariant mass). I have no doubt that readers will know what "at rest" means, just not that all of them will know why this is important here.
• "On the periodic table of the elements, atom size tends to increase when moving down columns, but decrease when moving across rows." - even though there's an earlier reference, it would be good to wikify "periodic table" here.
  • Done.
• Energy levels: Why not a single word about emission lines? From reading this, many readers are in danger of jumping to the conclusion that "spectral line" and "absorption line" are synonymous. Also, this would be a good place to at least mention fine structure.
  • I added a sentence about emission lines. Since it's a summary article, I'm not sure how much detail should be added. Perhaps it would be sufficient to expand on fine structure on the Atomic spectral line article?
    • I think it's fine (finely structured?) now!
• "Atoms tend to chemically react with each other in a manner that will fill their outer valence shells." - on reading this, few readers who aren't already in the know will realize that shedding electron, so what was once an inner shell now becomes the new, fully-filled outer shell, also counts.
  • Fixed.
• "The first nuclei of elements one through five" - this sounds as if there weren't any hydrogen nuclei before the 3 minute mark (and, incidentally, will leave some readers wondering why elements one through five is followed by a list of six).
  • Addressed.
• "Some atoms such as lithium-6" -> some atomic nuclei? some isotopes?
  • Fixed.
• Random search of references: ISBN 0-618-34342-3 appears to be wrong (five others were alright; is there a Wikipedia tool which checks for this kind thing?).
  • Are you sure you're looking at the right edition?[1]
    • I wasn't at any particular edition - just following the link and then using the link provided there to find the book in the Library of Congress and COPAC. Coming up dry in both (which is highly unusual for English language books), I thought there might be a problem with the ISBN.

All the best, Markus Poessel (talk) 21:54, 13 February 2008 (UTC)

Thank you for the comments.—RJH (talk) 16:48, 14 February 2008 (UTC)

My pleasure. -Markus Poessel (talk) 21:27, 14 February 2008 (UTC)

• Support Article is very well written and pretty informative. I made a few minor copyediting changes, but overall I think the article meets the FA criteria. I would recommend one minor change, though: I noticed that several masses are specified in kilograms, which seems a bit odd when referring to small things such as atoms -- the gram, not the kilogram, is the standard unit of mass in the metric system, and should be used here (a kilogram is simply 1000 grams). Dr. Cash (talk) 23:38, 13 February 2008 (UTC)
  • Thank you. I changed all instances of kg to g and scaled the values accordingly.—RJH (talk) 00:09, 14 February 2008 (UTC)
• Support simply impressive, good to see the chemistry articles are improving. (some of the element ones are still underdeveloped) igordebraga ≠ 01:27, 14 February 2008 (UTC)
• Support At a quick look this is an FA article. The only minor concern is that the see also section might be a bit long. Make sure the stuff there is not allready in the article. If it was me, I would move the ionization into the article, maybe close to the valence section. Otherwise this looks good. Nergaal (talk) 03:59, 14 February 2008 (UTC)
  • Ionization is covered briefly by the last section of "Electron cloud". I thought it was important to have at least a tie-in to the chemical properties of atoms, so that's the reason for the brief valence section. (It has been trimmed down quite a bit.) I'll work on trimming the "See also" section. Thank you.—RJH (talk) 15:37, 14 February 2008 (UTC)

• Support. Just one question: where it says "...atoms forms about 10% of the mass of the galaxy", what's the other 90%? Dark matter? If so, perhaps it would be worth mentioning and linking so that interested readers can learn more. (The reference for that statement is a book, which is not that easily accessible.) --Itub (talk) 17:31, 14 February 2008 (UTC)
  • Okay, I inserted a brief note about this. (I was concerned that mention of dark matter might require an off-topic explanation, but perhaps not.) Thanks.—RJH (talk) 21:25, 14 February 2008 (UTC)

• Support - a double read-through didn't find any concerns not already mentioned, and those seem quite minor. This certainly meets the featured article criteria. Nihiltres^{t.l} 18:44, 14 February 2008 (UTC)

• Support - I passed this article to GA status last week and felt it was practically at FA then. Kudos to all the editors who've worked on it! --jwanders^Talk 19:46, 14 February 2008 (UTC)

• Weak oppose I'm not sure all the sources are top-class reliable, there are quite a number of newspapers and online teaching, an e-mail, and some research institute homepages. Narayanese (talk) 22:11, 14 February 2008 (UTC)
  • Where are you seeing the e-mail? I think that for some of the references I chose links that would also provide some "additional reading" for interested viewers. I certainly don't see a problem with using university course material from solid institutions. Where the reference seemed a little soft I usually looked for a second.—RJH (talk) 15:45, 15 February 2008 (UTC)
    • The e-mail refernce is for the number of atoms in the universe. You're right that the dual book/journal+online lesson references are a nice touch. The muonic atom paragraph could use another ref, as does the 1 fm strong force distance.Narayanese (talk) 16:18, 15 February 2008 (UTC) Fixed (I realise the strong force cite was higher up) Narayanese (talk) 22:53, 15 February 2008 (UTC)

Comment It would be useful if all the printed references were collected & presented in the form of an alphabetical bibliography. This would make it a lot easier to find that interesting quotation from, say, Feynmann. As it stands, the References section is too long & unwieldy: I suggest renaming it Notes, & calling the new bibliography References.

• Support Apart from this quibble, though, I think it's an excellent & clearly written article. The lead is especially good. --NigelG (or Ndsg) | Talk 12:33, 15 February 2008 (UTC)

Thanks for the comment. There is little or no re-use of references in the list, so I don't believe that presenting it in an alphabetical bibliography would shorten it in the least. In fact I expect it would double the length as you'd have to then reference the bibliography. As for the current length, well it is as long as it needs to be. It's far from the longest on wikipedia. So... all I can say is I'm sorry you don't like it. =)—RJH (talk) 15:49, 15 February 2008 (UTC)

:::I don't think it's just a matter of personal preference, so I'm not letting you off the hook that easily! The article would become so much more useful & user-friendly if it had a proper bibliography rather than a large number of references hidden away in the notes. A quick count suggests there are over 30 books in there trying to get out.

Done.—RJH (talk) 19:53, 16 February 2008 (UTC)

Thanks! A great improvement IMO. I added a couple of page references (Liang & H, & Teresi) in the footnotes that had disappeared in the process. --NigelG (or Ndsg) | Talk 20:51, 16 February 2008 (UTC)

:::Overall, my suggestion might make the article marginally longer; but the Notes section (ie the current References) would be shortened, since several entries would simply be of the form Harrison (2003). But if other editors are as happy with the present format as you seem to be, I'm not going to oppose. --NigelG (or Ndsg) | Talk 18:58, 15 February 2008 (UTC)

I think I see what you're getting at. I mean, the point of current reference is to give sources for all facts given in the article—is what you're looking for is more of a "Further Reading" section that would give direction to readers seeking more information? If so, this sounds like a good idea, but I don't think it needs to include every book the article references. Maybe if 5 or so books were listed? --jwanders^Talk 20:34, 15 February 2008 (UTC)

• Comment The definition of half-life in Atom#Radioactive_decay is of course correct. I wonder, though, whether it might not be useful to spell out the fact that after 2 half-lives a quarter of the original isotope remains. Not every reader will be familiar with exponential decay! Just a suggestion ... --NigelG (or Ndsg) | Talk 12:41, 15 February 2008 (UTC)
  • Done.—RJH (talk)

Thanks: looking good. --NigelG (or Ndsg) | Talk 18:58, 15 February 2008 (UTC)

• Support for an excellent article, certainly one of the best I've read.--GrahamColm^Talk 16:52, 16 February 2008 (UTC)
• Support - prose balances succinct plain-english word usage without losing meaning well. fulfils other criteria cheers, Casliber (talk · contribs) 20:30, 16 February 2008 (UTC)

• Support I participated in the peer review of this article and I think that in the current form it satisfies FA criteria. Ruslik (talk) 17:59, 17 February 2008 (UTC)

The above discussion is preserved as an archive. Please do not modify it. No further edits should be made to this page.