Talk:Atom/Archive 2

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Contents

New input on article needed

12/12/05 Dear Xerxes314 and ALL other readers of this page. Please do proceed to give detailed constructive criticism of flaws in the article, any errors, any sentences that do not make sense, and any problems with logical sequence and structure. I believe that there is no need to include any more detailed information since I am told this is an "introductory article" on the atom. However, I am a published author, I've done research for an R&D lab for the past ten years, and I'm trying to help improve the content of Wikipedia along with many others here. I can rewrite this article to very technical specifications if that is what is called for. I've written in a colloquial manner having in mind readers who are unconversant in chemistry and physics and for the young as well. I think new input is needed on the current state of the article. --Voyajer 01:28, 13 December 2005 (UTC)

This is pretty much exactly what's wrong with the article. The colloquial tone has allowed factual errors to creep in under guise of friendly vocabulary. An encyclopedic source of information needs to be technically correct first, especially in the case of the Wikipedia, where you're never more than a click away from further explanation of any unfamiliar terms.
As a further example, take the new picture at the top. It's still dead wrong in picturing what an atom is like. Instead of little yellow balls, we now have little gray sine waves. A schematic is a schematic. It shows you that atoms are made up of three things, and vaguely indicates where they're located. Worrying about whether quantum mechanics is involved is beyond the scope of the picture. So you've made a change that makes things more complicated, but not more correct.
PS - This reads as grumpy even by my standards, but I'm too tired to further edit it. Please try not to be too offended. -- Xerxes 04:28, 13 December 2005 (UTC)
      • I don't think you were being grumpy, just opinionated. But who isn't? There were many complaints before I got here on using the Bohr model. You said I made the model of the atom "more complicated". I believe this isn't true. Children pretty much get used to believing what they are taught in school from the images that they are shown. Children in school are still shown images of the atom as a planetary system which is what Bohr still thought in 1915. He really didn't change the Rutherford model much except to include quantum theory which is not shown in a Bohr model of the atom. Rather a Bohr model of the atom only succeeds in showing the atom as a planetary system. This makes it difficult in the transition to college where one has to re-learn the model of the atom. Introducing the wave concept and the spherical concept of the atom into elementary models is not "more complicated". It gets people used to the idea that the atom is not a miniature solar system. It makes the transition to physics much easier. It puts people's thought about atomic theory on the right path. Certainly looking at the Bohr model for the first time is in itself complicated. We are just used to seeing it and therefore think it isn't complicated. The picture of the Helium atom model that is now represented is what Stephen Hawking and other physicists use as the simplest, most uncomplicated way to describe current atomic theory. Instead of creating a basis where individuals have to "unlearn", it creates a "jumping off point" where people constructively can begin to learn more about the atom. Yes, it begs questions, but the questions are valuable. Simply using a Bohr model of the atom may make people feel comfortable if they are familiar with the models of the solar system, but it isn't our place to make people feel more comfortable but to present a better representation of the reality of the atom. And no model of the atom is going to be a real picture of the atom. A model must just represent current theory in the clearest form possible within its limitations. Your comment that the new model of the atom is "dead wrong in picturing what an atom is like" should actually be taken up with Stephen Hawking since although I did the computer graphics for this particular pic, he came up with the idea or copied it from other physicists (I copied the model from his books). If modern physicists choose this model of the atom with its "sine waves" as the clearest visualization possible, I believe it should stand. --Voyajer 17:45, 13 December 2005 (UTC)
        • By the way, I agree that the tone was too colloquial and have edited it. However, comments on where it is still too colloquial would be appreciated. Voyajer 17:49, 13 December 2005 (UTC)
It's not how real physicists think of the atom. The pictures in the quantum mechanics section are how we think of the atom. However, the picture at the top is meant to be a schematic, so it does not need to take quantum mechanics into consideration. The original picture both worked as a schematic and had historical importance. Also, the new picture is misleading in that it does not present the nucleus as being quantum mechanical; it is no different from the electrons in this respect. -- Xerxes 19:11, 13 December 2005 (UTC)
      • First of all, the present model of the atom is still a schematic. It is merely a 3-D schematic. As far as the nucleus also having quantum effects, this model is portraying a fanciful nucleus at rest and the electron relative to a motionless nucleus. Yes, I know that that is not reality, but it is incidentally how physicists at the beginning of the 20th century had to begin their calculations in order to produce any theories of the atom at all. Secondly, I think you are arguing with the wrong person. I didn't invent this model of the atom. See Stephen Hawking "The Illustrated Brief History of Time". The pictures on page 79 describe the sequence of "the evolution of the atom" and portray models of the atom as theory has evolved. The last picture shows a 3-D model in a spherical shape with waves on the surface of the sphere as the closest depiction of a model (or since you prefer the word: 3-D schematic) of the atom according to current theory. Models or schematics are not easy to develop for complex systems. How do you draw a schematic of a probability cloud without obscuring the nucleus? How do you draw a schematic that defines the electron as essentially everywhere in its atomic orbital at the same time? Well, obviously Stephen Hawking and other physicists thought that the best schematic for describing an atom was not to show the electron as a particle since it is hard to grasp that a particle, in and of itself, surrounds the nucleus. Remember this is not my idea. It is a simple model of the atom, a simple 3-D schematic, that clarifies as much as can be clarified in a model, the current view of an atom in the simplest form possible that Stephen Hawking and other physicists could come up with to teach the public in a non-technical article about what a schematic of the atom should look like. They needed to come up with a schematic that would NOT represent a single stationary measurable electron. This is their idea of how to solve the problem (not mine). I believe there have been enough complaints here with the Bohr model being used as a schematic. I believe that Stephen Hawking's 3-D schematic whether he invented himself or borrowed from other physicists presents a clearer picture for the general public. Thirdly, this model of the atom does have historical significance. According to Hawking, it is the "Schroedinger model" of the atom.--Voyajer 18:40, 14 December 2005 (UTC)
Assigning the blame to your misinterpretation of Hawking's pop-physics hand-waving does not make a bad diagram good. This may surprise you, but "Brief History of Time" is not considered a canonical reference; it's certainly not of any historical significance. The "Schroedinger" picture is already presented in the article in the section on the electron configuration. What the article needs is its original "Bohr" model schematic back, which is of historical significance and neatly depicts the three components of the atom. -- Xerxes 20:36, 14 December 2005 (UTC)
  • Okay, now I would say that you are simply displaying bad manners. However, despite your distaste for Hawking or his literature, you must respect that he made himself a name in physics prior to "Brief History of Time" and that there is even a type of radiation named for him. He was the leading expert in Black Holes in the 70s along with Roger Penrose. He took the seat of Isaac Newton at Cambridge in 1979. I think it would not be an understatement to say that he probably knows a little more about physics than you and I do. Show some respect. Also, I very much doubt that his portrayal of the atom is anything but based on solid science to the extent that a model can be. In 1927, Davisson, Germer and Thomson proved experimentally the existence of de Broglie waves (matter waves) of the electron, using the diffraction by Ni crystals. In 1926, Schroedinger developed his "wave mechanics" based on the theories of Planck, Heisenberg, Einstein and de Broglie. To show a schematic of the electron as a particle is contrary to good science. The mere fact that you have resorted to character assassination instead of appealing to logic is proof in itself that you are being a little hardheaded and unscientific. The purpose in Hawking's writings albeit was to make money, but NOT to mislead the nation or the general public about the depiction of the atom. The bottom line is neither you nor I should be making this decision. It should be a matter of consensus. It does not appear to me that there was a consensus about the Bohr model before I arrived here. --Voyajer 21:13, 14 December 2005 (UTC)

Sorry VSmith, I'll post to bottom from now on. Just thought new posts seem lost that way.

Regarding my changes to article that I'm not entirely happy with myself was the necessity to include information on atomic orbitals in the "atom size" section. Previous to my added introductory paragraphs, the size of the atom section began with this sentence: "The size of an atom is not easily defined since the places where the electron can be just gradually go to zero as the distance from the nucleus increases."

Now I don't know about anyone else, but I'm tolerably familiar with physics and quantum mechanics and that sentence seemed way out in left field. After reading it several times, I realized that the "atom size" section was beginning with a sentence on "probability distribution" of an electron in an atomic orbital slowly dropping to zero at the exterior of the probability cloud. Now this is the first section of an introductory article on the atom and the first paragraph after the intro starts out with a sentence that can only be understood by someone with a certain grasp of quantum mechanics. That seemed too big a leap to me. I therefore resolved the issue by introducing the atomic orbital in relatively simplistic terms. However, I am not entirely happy about including information about the atomic orbital in the "atom size" section. The other solution would be to completely wipe the sentence about electron distribution gradually going to zero and simply state the size of the atom. Any comments?

I am in favor of keeping information related to "seeing the atom" in this section due to this being a common fallacy. And I am generally in favor of keeping information in the article on various shapes of atomic orbitals, but would not mind seeing this explanation under a different heading.

Aside from the fact that "study of the atom" could contain more information, I feel that the article contains all the information requested in the WikiProject "pending tasks" list above. Aside from a few clumsily worded sentences (including some of mine), I think the article satisfies the requirements. Any suggestions and comments would be appreciated not only by me, but by others working on this article. Voyajer 03:42, 13 December 2005 (UTC)


i have added information on the bitrh of the atom and how is was formed after the big bang, how accurate it is i am not sure, it is mostly from memory. Should i have suggested before posting the information, because im not sure how accurate it is. Delete as necessary if inaccurate Divad89 02:14, 1 December 2006 (UTC)

Is this true?

"Several elements that do not occur on earth have been found to be present in stars."--I forgot who added this sentence.

Stars use fusion to create elements but cannot create elements heavier than iron (the 26th), and the rest of the heavier elements are created in supernova explosions. Therefore, is it true to say that several elements not occurring on earth are present in stars? Are they not rather present in nebulae or interstellar dust and gas? Does someone know off-hand or should I research? Of course, the sun itself has trace quantities of the heavier elements because it is at least a second generation or third generation star that has incorporated elements created in supernova explosions. So did I just answer my own question?--Voyajer 16:45, 13 December 2005 (UTC)

Yes, it is true. There are trace amounts of things like Technecium and ultra-heavies.
Also, could you try to make fewer than a dozen edits a day? It's impossible to keep track of the changes when you make more than a full page worth between each time I check back. -- Xerxes 17:04, 13 December 2005 (UTC)
Yes - please use Edit summaries, and preview rather than save each bit, combine bits and save a bigger batch. It would be appreciated, Thanks, Vsmith 17:22, 13 December 2005 (UTC)

I didn't think it was that important how I edited, but in future I will do my best to comply. Voyajer 17:52, 13 December 2005 (UTC)

Removal of Practical Uses section

The text in Practical Uses of the atom felt very superfluous. It was far too vague. (written by Kurzon)

  • I agree ... except for the fact that the pending tasks for this article was to contain information on "atoms in industry" fusion, fission, etc. Removing the Practical Uses section simply leaves this task "still pending". And creating a detailed account of fusion, fission, and the atom in different fields of science is redundant since there are specific articles discussing these subjects. How does removal of the Practical Uses section help with alleviating the pending task of describing fusion, fission, and atoms in industry? Explain instead how to improve. I didn't like the section itself except that it met the requirements for the pending tasks. It was a "jumping off point" for further investigation of these areas without going into details. Removing it solves nothing. Now the task still remains.--Voyajer 21:59, 14 December 2005 (UTC)

If you ask me, the pending task "atoms in industry" should itself be struck off. It's just not a practical task. Who put it forward anyway? The "atoms in science" one is OK; it might be interesting to list a few ways atomic strucutres can be observed. Kurzon 23:01, 14 December 2005 (UTC)

  • I was just about to ask the same question. No encyclopedia article on the atom that I can find has a section on "atoms in industry". However, they do carry sections that we are missing, such as: radioactivity, and the forces acting within atoms i.e. the strong force, weak force, EM force. I would think these sections would be more apropos.--Voyajer
    • Since all normal matter is made of atoms, any attempt to do an "atoms in industry or medicine" or the like is totally doomed. Yep, it all uses matter, ie, stuff. To have any HOPE of keeping this section or sections like it manageable, I propose it be limited to use of SINGLE atoms in industry, for example the new timekeeping devices which use single barium atoms in a trap, excited by a laser. And so on.Steve 13:36, 30 June 2006 (UTC)

Atomic Theory and Historical Theories

The article on atomic theory is more or less like the historical theories section we have here. I think that article should be merged with this; it's redundant.

Speaking of which, is their a posh word for the historical development of a scientific theory? As how "etymology" describes the historical development of a word?

  • I believe this is a good change. I don't believe there is another term. Your choices are: Historical timeline of atomic theory, Chronology of atomic theory development, Sequential atomic theories, Evolution of atomic theory, and Historical development of atomic theory. I think the last two are preferable, but go for it.--Voyajer 05:26, 18 December 2005 (UTC) -- I should also add: Progress of atomic theory and simply Development of atomic theory to your choices.
I will merge the History of Atomic Theory section to the Atomic theory article. It might take some time Heavy Metal Cellist talkcontribs

what does an atom do when it is heated

well, basically heat comes from the clash between a free electron and a stable atom, and free electrons are produced by the destabilization (alteration iun the amount of Electrons, usually becouse of elemental combinations sucha s oxidation) of an atom. So you cant really heat an atom. That, or it might increase the speed and orbit of the electrons, given the greater amount of energy, this however may result in the loss of the electron, and so you'r back at the first theory.

who discovered the atom?

well?

Pece Kocovski 07:53, 3 February 2006 (UTC)

There's no simple answer. Just read the article and look at the history. Itub 16:57, 3 February 2006 (UTC)

Atoms?

Has anyone seen them? I belived not, but recently I was told a profesor of mine owns a Picture of one, or so he claims, taken by a electronic microscope. Can anyone tell me if it is true? If so, Why isn't there a picture of one? Thnk you.--201.208.149.194 02:42, 7 February 2006 (UTC)

Yes, there are images. There is not a good one in the Wikimedia commons. Presumably people with expensive equipment are not keen on letting out their expensive images. Here's a link to a famous series from IBM: Atom Corral -- Xerxes 18:22, 7 February 2006 (UTC)

History of Atomic Theory

My main goal when editting this section was to clearly explain the logical steps scientists made over the years in developping atomic theory, in a sweet and simple manner that is clear to the layman, ie people who have a decent IQ but are not physics students who have lived and breathed this stuff for years. Throwing lots of unclear jargon around as well as vaguely referencing contributions without explaining their significance goes against this principle. The following paragraph is a good case in point:

"The ad hoc Bohr model would eventually be replaced by the Erwin Schroedinger's Schroedinger equation in 1925. Together with the Pauli exclusion principle, this allowed study of atoms with great precision. Even today, these theories are used in the Hartree-Fock method to determine the energy levels of atoms. Further refinements of quantum theory such as the Dirac equation and quantum field theory made smaller impacts on the theory of atoms."

What the heck is the Schroedinger equation? Why did it replace Bohr's concept? Just how did that and the Pauli exclusion principle allow the study of atoms with great precision? All this paragraph really says in the end is that the model of the atom kept developing after Bohr. I feel this is inadequate for an informative encyclopedia. Perhaps doing these developments justice would require an inordinate amount of maths and explanation, but we should at least try to offer something sweet and simple.Kurzon 19:48, 7 February 2006 (UTC)

Well, I haven't got my atomic physics book on me at the moment, so I couldn't remember the major failings of the Bohr model. Inability to calculate transition rates is one. Inability to deal with multielectron atoms is another. What did you have in mind? -- Xerxes 20:12, 7 February 2006 (UTC)

==Better image==

A semi-accurate depiction of the neutral helium-4 atom. The darkness of the electron cloud corresponds to the line-of-sight integral through the probability function of the two-electron 1s electron orbital. The inset nucleus magnified 150 times; it is schematic, showing two protons in red and two neutrons in blue. In reality, the nucleus is spherically symmetric.
A semi-accurate depiction of the neutral helium-4 atom. The darkness of the electron cloud corresponds to the line-of-sight integral through the probability function of the two-electron 1s electron orbital. The inset nucleus magnified 150 times; it is schematic, showing two protons in red and two neutrons in blue. In reality, the nucleus is spherically symmetric.

I still think the image is no good. Here's my first attempt at an improvement: -- Xerxes 20:12, 7 February 2006 (UTC)

Zoomed out a bit to show the bounds of the atom. Added scale information. -- Xerxes 18:49, 10 February 2006 (UTC)

Yes, I agree that this is a better picture. Itub 19:02, 10 February 2006 (UTC)
One thing I think this image really fails to convey is the fact that atoms are spherical. Any ideas on how to improve it in that respect would be appreciated. -- Xerxes 19:24, 10 February 2006 (UTC)
That's hard, because 3d pictures of orbitals tend to look like solid balls (or balloons). I don't know how one could make a diffuse cloude look 3d. Itub 20:31, 10 February 2006 (UTC)
When this is resolved, could the same image be placed at atomic nucleus, please! Olin 03:36, 29 March 2006 (UTC)

Last reversion

1) The atom is not empty space. It is densely filled by the electron cloud.

2) The Bohr model was not constrained to cicular orbits. It also handled elliptical orbits of fixed angular momentum.

-- Xerxes 20:21, 7 February 2006 (UTC)

Both points are debatable: 1) there may be some electron density everywhere, but I wouldn't call it "densely filled". The probability of observing an electron as a particle in any specific place is very small. 2) the original Bohr model did use only circular orbits. Elliptical orbits were added in the Bohr-Sommerfeld model. The thing that I would say is most inaccurate about the edit in question is that it said that the alpha particles in the Rutherford experiment "struck" the nucleus. Itub 23:45, 7 February 2006 (UTC)
Well, it's densely filled in the sense that the electrons are degenerate. There is no physical way to pack more electrons into the space around a nucleus than you already have in the ground state. The history of atomic models could be more detailed tho. Certainly Sommerfeld deserves a mention. -- Xerxes 00:11, 8 February 2006 (UTC)

OK, the same "empty space" nonsense has been reinserted into the article. The only difference is that now Rutherford is accused of making the incorrect statement. On the contrary, Rutherford clearly states in his 1911 paper (Section 7, General Considerations):

In comparing the theory outlined in this paper with the experimental results, it has been supposed that the atom consists of a central charge supposed concentrated at a point, and that the large single deflexions of the α and β particles are mainly due to their passage through the strong central field. The effect of the equal and opposite compensation charge supposed distributed uniformly throughout a sphere has been neglected.

The emphasis is mine, but the point is clear. -- Xerxes 17:14, 8 February 2006 (UTC)

I don't agree. Even if he didn't actually use the word "empty" in that article, it was implied, because electrons were already assumed to be tiny particles at the time, and their mass and charge were known. He talks about electrons moving rapidly around the atom, which can only imply that there was empty space between the nucleus and the electrons. Also, there are literally hundreds of books that explain Rutherford's experiment in terms of empty space: [1]. I haven't found a single book yet that says the contrary. Itub 19:16, 8 February 2006 (UTC)
It would hardly be the first time books for a laymen audience picked up a nonsense phrase and ran with it. The volume of an atom is not empty; it's filled with electrons. If Rutherford did not know that in 1911 nor Bohr in 1913, it was certainly understood by Schroedinger in 1923. What is the point of emphasizing a idea that is today known to be incorrect and was only wrongly believed for 12 years (if ever)? -- Xerxes 19:35, 8 February 2006 (UTC)
You would call Max Born and Otto Frisch laymen? (Edit: sorry, you were referring to the audience of the books as laymen. In any case, Born's Atomic Physics seems rigorous enough.) They wrote two of the books refered to above. You are just choosing one particular interpretation of quantum mechanics and basically redefining the word "empty" in such a way that there can be no empty space! Yes, you can't pack more electrons, because they are fermions. But you won't have trouble having other types of particles moving freely through the empty space in the atom. And even if a concept were to be disproved, this is a section about the history of atomic theory. You need to discuss each discovery in its proper historical context. In any case you could create a properly referenced article about the Empty atom controversy (if such a controversy exists) and link it from the Atom article. Itub 20:02, 8 February 2006 (UTC)

Image problem

As Bensaccount correctly pointed out, the density function of the image was incorrect. I don't think the replacement image had a correct density function either, since it had sharp cutoffs, so I went ahead and made another version. The new version of the image (I think) has the correct electron density profile. The nucleon profile was grepped out of a nucl-th paper. Again, the nucleus is really almost spherically symmetric, but artistic liberties have been taken. The nuclear scale bar is another good feature taken from Bensaccount's image. -- Xerxes 21:38, 11 May 2006 (UTC)

Wikipedia:Version 0.5

I've failed the article for inclusion in the release because the antimatter section is too short. After this section is expanded, it would be a good idea to add inline references to it, unless the entire article is indeed based on only one textbook. Titoxd(?!? - help us) 01:30, 30 May 2006 (UTC)

This makes no sense. Atoms have virtually nothing to do with antimatter. The brief mention in the article is completely appropriate for the relevance of the topic. -- Xerxes 01:47, 9 June 2006 (UTC)

History of atomic theory

I think that linking to other article is fine but there should be some information on the devlopmanet of the theory, so I have reincluded some of the history section. I hope it isn't too large! Rex the first talk | contribs 17:06, 18 June 2006 (UTC)

I think maybe a link to the article and a mention of who discovered the atom and who came up with the present model are all that are needed. Remember, this article is about the atom, not the history of atomic science. Since this articl is so big, all it needs to do is give a basic understanding of what an atom is, how it works, why it's important, and which articles can tell you more.

I rewrote the historical section into something more condensed. The previous version was a little long, and not very elegantly written as it was a hack-job of extracts taken from earlier versions of the atomic theory article. Feel free to correct any mistakes I made, but please keep the section concise and elegant; we have a dedicated article that explains the history of atomic theory. Kurzon 08:28, 11 July 2006 (UTC)

How do they stay together!?

If a proton has a net Positive charge, and a neutron has no charge... then how do they stay together!?

(please use my talk page to respond) Tinlv7 18:33, 21 August 2006 (UTC)

never mind

Fixed the page

I fixed the vandalized page. Should it be tinkered with further by vandals, we should lock it. 03:18, 14 September 2006 (UTC)

RE: Sep 14 edit

RE:

Atoms with the same atomic number Z share a wide variety of physical properties and exhibit almost identical chemical properties (for the closest instance to an exception to this principle, see deuterium and heavy water). Atoms are classified into chemical elements by their atomic number Z, which corresponds to the number of protons in the atom. For example, all atoms containing six protons (Z = 6) are classified as carbon. The elements may be sorted according to the periodic table in order of increasing atomic number. When this is done, certain repeating cycles of regularities in chemical and physical properties are evident.
  • RE: Atoms with the same atomic number Z share a wide variety of physical properties and exhibit almost identical chemical properties (for the closest instance to an exception to this principle, see deuterium and heavy water).
    • I see nothing in deuterium article about it having different chemical properties than hydrogen - maybe I just missed it so far? I do a brief mention that deuterium compounds behave chemically slightly differently :* --JimWae 19:29, 14 September 2006 (UTC)
Well, if the compounds behave differently, that's due to the chemistry of the deuterium (deuterium doesn't necessarily refer to pure D2 gas, but also D atoms whereever they are found). SBHarris 18:53, 1 October 2006 (UTC)
    • introduction of Z without explanation presumes reader is already familiar with it
  • RE: Atoms are classified into chemical elements by their atomic number Z, which corresponds to the number of protons in the atom.
    • We do not examine the number of protons in an atom to determine what element it is. While the above does not directly state that we do, it leaves that impression because it does not talk about any other way we do use to tell elements apart
  • --JimWae 19:29, 14 September 2006 (UTC)
Okay, this needs a bit of fixing for beginning readers. No, we don't count protons. We do separate by chemical behavior, which amounts to the same thing. SBHarris 18:53, 1 October 2006 (UTC)

proof of existence

I think there should be a section on how atoms have not been directly observed (afaik), and how they are posited as entities simply because they help explain and unify various scientific models and theories. This, imho, is one of the interesting parts of atomic theory.

With atomic force microscopes and scanning tunneling microscopes, individual atoms have been visualized in the same way that viruses have (we need some links in this article for that-- I'll get to it). I'm not sure what you mean by "directly observed." No, not with the eyeball. However, a decade or so ago IBM used 35 individual xenon atoms to spell out "IBM" on a metal surface [2], and that's hard to do if you can't in some way "observe" the individual atoms. Do you think viruses are still just posited entities? DNA molecules? How far down in scale does your philosophical skepticism extend? SBHarris 17:34, 1 October 2006 (UTC)

Metals not molecules?

The intro says:

For gases and certain molecular liquids and solids (such as water and sugar), molecules are the smallest division of matter which retains chemical properties; however, there are also many solids and liquids which are made of atoms, but do not contain discrete molecules (such as salts, rocks, and liquid and solid metals).

I see no discussion later about how metals are not molecules. There is mention that single atoms CAN be considered molecules. I suppose there is some thought regarding crystals here, but "rocks" seems unneeded also --JimWae 17:00, 1 October 2006 (UTC)

Single atoms are considered molecules only if there's a lot of space between them, as in gasses. I'm not sure we need any additional reasons why metals are not molecules. Metals are made of crystals and if you accept that crystals are not molecules, you're already there. Melted metals are obvious atoms sliding over each other-- there may be globs or more than one atom at some temperatures, but not orderly numbers of globs in metals, such as the 3-atom globs in liquid water. Thus, no "molecules" as we know them.

As for the mention of "rocks," it's needed. The earth is made of rock with a metal core. Thus, most of what you're standing on is NOT made of molecules, or a molecular material in the same way that (say) sugar or ice are. That's worth special emphasis. Molecules are common on Earth, but most of the Earth is not made in a molecular pattern. SBHarris 18:43, 1 October 2006 (UTC)


  • If a molecule is defined as the smallest unit of a substance that retains its chemical properties, then many monatomic elements would count as molecules. Yes, but this is by no means the single accepted definition of the world molecule, a fact which has been extensively discussed on the molecule wiki (see the TALK page) but which doesn't deserve to spill over here. In fact, one of the difficulties of using the above definition is that if universally applied, it would force exactly the usage for metals and non-gaseous "noble" elements which you imply that it should. Except that in reality it doesn't. No text or published paper refers to metal molecules, unless they occur in gas phase, or (say) trapped as 2-atom bimetalic well-defined compounds in some other solid phase [3]. Nor do physicists refer to liquid helium molecules (say), except when they are referring to dimers and larger collections. Single atoms as molecules are only linguistic features of He gas, not liquid or solid. [4] Monatomic components of He liquid are referred to as "atoms," but in gaseous helium they may be, and usually are, referred to as "molecules."

    Now, you may complain that this is inconsistant with your favorite definition, instead of one of the other definitions of molecule you'll find in the LEAD section of molecule. That's too bad. It is inconsistant with your favorite definition, but that only means that the definitions under consideration are inconsistant with each other, and no single definition of "molecule" is used universally and in all circumstances by all working scientists (chemists and physicists). Even if you think it ought to be.

    Ironing out the linguistic consistancies in the language of chemists and physicists is not your job. And it's certainly not good to drag the problem onto this page on atoms, where discussion of the controversy and consistancy problems of the word "molecule" don't belong. It is proper to note that single atoms in metals and rocks and nobel liquids and solids are not said to be "molecules" by scientists, for this usage is universal. It's not the place to point out that maybe such atoms SHOULD be called molecules in some of these circumstances, if all scientists, all the time, and with complete consistantly, used ONE of the definitions of "molecule" which you happen to favor, and which you have found used in some dictionaries. So? Take that argument to the "molecule" talk page. Complain to IUPAC. Not here SBHarris 19:51, 1 October 2006 (UTC)

  • I am so disgusted with your tone & arguments ad hominem that I decided NOT to finish reading your comments yet. I did read far enough to see that it is you who is including your favourite definition as the wiki definition --JimWae 19:55, 1 October 2006 (UTC)
  • I am using not my favorite definition, but rather the definition used by working scientists, of which I gave you two example paper cites from the relevant current scientific literature (feel free to give me counterexamples FROM the literature). This is how working physicists and chemists use the term in current research. You are free to use definitions given by dictionaries and Chem 101 sites, and you are free to think I'm being ad hominem to suggest to you that this is not the place for you to worry about that. Have a nice day. SBHarris 21:18, 1 October 2006 (UTC)