Talk:Atom/Archive 1

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What is there between The Nucleus and the Electrons?

I Have been wondering this. There cant be air, for air is consisted of atoms and we are talking about sizes smaller than the atom. There cant be nothing becouse, well, nothing dosn't exist. i have been told that a Hipothetical vacuum, however the source is quite unreliable. Any thought on this? Thank you.

There is no space between the nucleus and the electrons. Check out the picture of the atom. The electron cloud fully fills the entire volume of the atom. -- Xerxes 17:39, 24 April 2006 (UTC)

Discussion

New talk at bottom of page.

I'm not sure a general rule regarding "less valence electrons means more reactive" is applicable. Fluorine and the other halogens are highly reactive, and they all have only 1 electron missing from their valence shell. Ed Sanville

uncut or uncuttable (indivisible)?

a means not and tomos means cutting. atom is typically translated with indivisible. I'll change it. AxelBoldt

I removed "even smaller particles which appear in nuclear reactions. The smaller particles (electrons, protons and neutrons) can be observed in many non-nuclear reactions; electrons are flying at your computer monitor and protons are swimming around in water and determine the PH. AxelBoldt

I'm picking nits here, but the proton example is not very good. While it is convenient to think of H⁺(aq) as a free proton that "swims" through the water, in reality it just isn't so. The proton is actually always surrounded by a coordination sphere of water molecules, with which it shares electrons (and is essentially covalently bonded). Sometimes this is represented as the formation of a hydronium ion (H₃O⁺), but even this is a simplification. In reality the extra proton is constantly interacting with multiple surrounding water molecules (and is likely exhanging places with hydrogen atoms in those molecules). Matt Stoker

I love etymology but I'm not sure that all encyclopedia users share my enthusiasm. Wouldn't it be better to relegate it to a sub-heading at the end? Unless, of course, the etymology actually has some bearing on the topic. What do the panel think? -- Heron

I agree with that assessment. When someone looks up atom, they most likely don't care that much about the etymology of the word. The same applies to most scientific topics. Ed Sanville 28 June 2005 18:27 (UTC)

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How large is the estimated number of atoms in the universe?

Well, according to this definition of the term "googol", the number of particles in the Universe is estimated to be between 10^120 and 10^130. Since an atom is made up of particles, that means the number of "atoms" in the universe is considerably smaller than that. Under a googol, perhaps?

Currently, the best information we have suggests that the universe, and the number of particles within it, is infinite. The links above probably talk about the observable universe, which consists of those parts of the universe which are close enough so that the light emitted by them has already reached us. AxelBoldt 23:45 Oct 12, 2002 (UTC)

If I remember correctly there are/were some theories saying that the universe is finite, although very large. I would be interested in knowing more about this. Who thinks what why? Any pointers?

It is, of course, possible that the universe is infinite in size but finite in number of particles. anthony (see warning) 00:40, 20 Aug 2004 (UTC)

I have not recent data at hands, but the total mass of the universe is a very often cited data (it is also very questioned becouse is very difficult to extimate and its value has impact in the way the universe is exmpandig and evolving).

In the view this is only an extimation I will use the value I have found at Orders of magnitude (mass) 3 × 10⁵² kg as the total mass of universe.

I will suppose that the universe is made only of Hydrogen (this is not true,I konw, but it is a rasonable approximation for this calculus). Since in 1 g of Hydrogen there is 6.022 × 10²³

Number of aoms in the universe ≈ 3 × 10⁵² kg × 1000 g/kg × 6.022 × 10²³ atoms/g = 1.8 × 10⁷⁹.

Please take care that this is only an extimation of magnitude! Do not take this as an exact number!! AnyFile 19:31, 26 Oct 2004 (UTC)

That's within the range I had added to the article, 4.0e78 and 6.0e79. Good to hear it from another source. Thanks. --Whosyourjudas (talk) 23:55, 26 Oct 2004 (UTC)

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Someone asked, in the following comment that I removed from the article:

(what was the name of the model Aristotle used? where atoms where like small pebble with different shapes)

I think the questioner was thinking of Democritus, the atomist, and not Aristotle, who denied atomism. Democritus believed that the properties of atoms were determined by their shapes. I put in a link to Democritus, but I think Democritus' idea should be discussed in this article. --Heron

Actually in his works Democritus does not concern very much on the phisical aspect, but the fellows of his theory (amoung with Epicurus and his fellows Epicureans, the latin Lucretius and other greek and latin atomistic or epicureans) does concern of it.

The problem, in my opinion, is that written as it is know, the sentence concern more to the Etymology sections. The Historic section is terrible small and only a list of link. But if you really want to written an historic section you have to consider also the philosophers contributions.

Before the science born as a separate discipline (and also later) philosofers do dealt whith argoment we now consider science.

After I have said this, that is of general consideration, in this particular case it should take in consideration that the atomic therory of ancient has only few connection with the modern one (the most important one is by no doubt the name atom). The ancient concept of atom is very different to the modern one both in physical and ideological aspect.

For that reason the ancient history could be short, but it shoulud be expanded. (Of course the modern history need be expanded even more.)

Consider that this article could be read by persons interested in this part of history (e.g. students of phylosophy at high scools). So a part on this should be insert. May be it could be a completely separated section (or sub section). May be it could be only a brief explanation that mention link, but not just a list of link, a complete explanation, even if brief.

I will try to contribute to this, but my high-school study are a little be distant in time. This part of phylosophy are a little be neglect in study becouse it is not consider important. This is not proble of today, but also in the ancient time the book of atomistic, epicureans and other considered minor schools have benne neglected in favour of more famouse philosopher (Aristotle, Platone). As a conseguence we noe have very little written matirial of them and very little study on them. AnyFile 19:39, 26 Oct 2004 (UTC)

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An atom is the smallest, irreducible constituent of a chemical system.

Come now, titans of chemistry! Surely, we can come up with a more concrete and more interesting introduction than saying an atom is part of a system. ("What system?")

Can we instead say that atoms are what you get when you take a blob of matter and break all chemical bonds in that blob, and then at that point each particle is an atom, it is a pure element, has an atomic number, might be able to form ionic or covalent chemical bonds with certain other atoms to form molecules, etc.?

So what's stopping you? Hop to it :-). -- Cyan

Need a better image

We really need a better image of an atom. The bohr model is ancient and inaccurate. In any case, I removed the caption "The electrons move rapidly around the nucleus." because that's just not true. Electrons exist as a standing wave which is "smeared out" throughout the orbital. The electron occupies all positions in the orbital at the same time. anthony (see warning) 00:38, 20 Aug 2004 (UTC)

The image of Bohr model is what, in my opinion, most people figure out what an a tom is. I do not know what a better image could be. Consider that in most simple explanation the Bohr rappresentation (I deliberately written rappresentation ins tead of model) could be enough. It could be enouth for simple exmplanation of a lots of simlple phisical and che mical phenomenon (in many of them it is enough to condider the whole atom as a s phere or as a disk of unspecified shape).

This of course is not a rappresentation of what modern physics consider an atom, but I really do not how an easy comprensible image could be. We can insert an image of orbital (a rapresentation of the probibility where an electron could be found in space around the nucleus), but it would be difficult to understen, it woul be the rappresentation of the electron around (or better speaking 'in the') atom, not of all the atom and there are lot of proble ms I can no cite here for brevity (for example the probability is a sum of a lot s of orbital).

In my opion it could be valuable an image of the atomical disposition in matter structure structure (the way the atoms dispone them in space). This image is of more interst of structural physics, cristallography, stereo-chemistry and other specific sectors, bur it could b e interesting here also (If matter is made of atom, how atoms made matter?) AnyFile 19:44, 26 Oct 2004 (UTC)

I went ahead and updated the Atom Image to show a probability cloud instead of a circular Bohr orbit. I know this is controversial and if people don't like the new image, I will put back the old one. Comments? ((PS: I also added a section discussing atom sizes)) FrankH 07:44, 13 Feb 2005 (UTC)

problem with proposed structure

the proposed structure for Atom (see the todo list at the top of this page) states that the first section should discuss isotopes, ions, valence, size, half-period, etc. without discussing theory. however, all of these are based in atomic structure, whcih is entirely theory (and is to be discussed in the theory section). I'm wondering if the structure should be re-written to integrate these sections into an overall atomic theory section that discusses properties and their theory-based causes. the article is already somewhat structured like that, and i've been working to clean up and clarify the current content. the wikiproject science guidelines don't seem to fit this article's content well. --Whosyourjudas (talk) 00:47, 11 Oct 2004 (UTC)

I agree the intro needs to include the theory behind all of it in abbreviated form and then expanded in the theory section. You have been doing a lot of work here. I've made some minor edits - will be back. -Vsmith 01:24, 18 Oct 2004 (UTC)

I needed a project - this seemed like fun :) Whosyourjudas (talk) 03:00, 18 Oct 2004 (UTC)

OK - modified proposed structure in to do list, needs more. Comments? -Vsmith 01:37, 18 Oct 2004 (UTC)

i did more modification to the to-do list - more in line with current article structure, but might still need work - article definitely does. Whosyourjudas (talk) 03:00, 18 Oct 2004 (UTC)

In my opinion information of what isotopes are, what are the size of atom and so on should be given, in a short form, at the beginning in the genral discussion. A reader should have a brief description of this in the general (and easy) sect ion without having the need to go in depth into more difficult section. As you say that there are different atoms whith different proton number, and th ey give raise to different element, you can shortly state that there are atoms w hith different number of neutrons and hence the isotope. The reason we are familiar to different element but not to different isotope is that in the grat part of our work we have to take into acccount difference betw een element (netween substance indeed) but we can ignore the isotope type unless we deal with nuclear problems.

Half-period: the radioactive aspect relate more to nucleus than atom. If you wan t to speak of half-period you could not give only the element type you have to g ive also the atomic number. The half-life are different from one isotope to othe r. In my opinion it is better only to give a link to another article (maybe radi active).

Studs of science! I've got a mind-blowingly basic question that must have a simple answer, though I've been quite unable to find a direct answer anywhere. Please set clear my cloudy head. So electrons are negative, right? And an atom's nucleus--thanks to those rather amicable protons--carries a positive charge, right? Why is it that everywhere else in science negatives and positives want nothing more than to get together like some microscopic gatekeeper and keymaster, yet when we turn to electrons and protons, the opposites are all about playing coy with each other? What gives?

A simplistic explanation is a satellite orbiting around a planet. The gravitational force attracts the satellite toward the planet, and there is no repulsive force acting in the opposite direct. (This is analagous to hydrogen with one electron.) The satellite's forward velocity is what keeps the satellite moving in an elliptical orbit rather than just plummeting toward the planet. Note: this explanation is not consistent with the quantum model! — Brim 19:49, Feb 11, 2005 (UTC)

atomic mass - mass number

The atomic mass or nucleon number of an element is the total number of protons and neutrons in an atom of that element, - this is ambiguous and incorrect. The mass number or perhaps atomic mass number refers to the number of nucleons in a nucleus. The atomic mass refers to the actual mass of the isotope or to the average mass of all the isotopes. Atomic mass is equal to mass number only for C-12 by definition. Binding energy effects make the atomic mass for all other isotopes differ from their mass numbers. The atomic mass is used extensively in stoichiometric calculations as the atomic mass in grams of a mole of the substance. Mass number or nucleon number are distinct from atomic mass and useless in stoichiometric work. This needs to be rigerously applied to avoid confusion. -Vsmith 16:30, 2 Nov 2004 (UTC)

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This may appear quite trivial, but I'm intrigued by the statement that ninety one elements occur naturally on earth. The generally accepted value is 92 (by search on Google at least), which is easy to understand (from a naive point of view) as a consequence of Uranium (92) being the element with the highest atomic number of the commonly occurring elements. But several elements (Technitium, Promethium, Actinium come to mind) are very rare in nature, and occur (almost) exclusively as decay products, so could arguably be excluded from the count. And to be fair, other elements (neptunium, plutonium) undoubtedly do also occur naturally via similar processes. So how do we arrive at the consensus of 92 (or 91 as used in the article)? If all elements were listed in order of abundance, is there a natural cut-off point at which we could decide the correct number to use? Sorry to be such a pedant, but I think that that some justification is needed here.

Looking at the article on Periodic Table, possibly a link to (and expansion of) Primordial Elements might be appropriate. And further, to be consistent with the Periodic Table article, the value should actually be 83 naturally occuring elements (excluding synthetic and decay elements (the distinction actually is broken in the article)).

-Kram 21:43, 12 Dec 2004 (UTC)

Link suggestions

An automated Wikipedia link suggester has some possible wiki link suggestions for the Atom article, and they have been placed on this page for your convenience.
Tip: Some people find it helpful if these suggestions are shown on this talk page, rather than on another page. To do this, just add {{User:LinkBot/suggestions/Atom}} to this page. — LinkBot 10:37, 17 Dec 2004 (UTC)

Coverage of "Element"

Is there too much information on elements in the article (being redundant with element)? This is an encyclopedia not a treatise/textbook (see WikiBooks) Dpr 03:36, 10 Mar 2005 (UTC)

Also see

Could we also consider added a 'Also see' page. Because Atom also happens to be the name of a popular content syndication format similiar to RSS. --Mayuresh Kadu (India) 04:02, 20 Apr 2005 (UTC)

Atoms and ions

This sentence reads a little oddly:

"Every atom has a number of electrons equal to its number of protons; if there is an imbalance, the atom is called an ion."

The first part seems to say that an ion is not an atom, the second part that an ion is a type of atom. --Edcolins 21:30, May 13, 2005 (UTC)

Help someone clean this up!

It's a mess! The whole Science and industry thing is a total farce! Atomic theory had a wide ranging impact on... chemistry?? Chemisty basically didn't exist before atomic theory (it was called alchemy before then)... Most scientific research associated with atoms is in the field of QM??? (what??) Atoms Serve many important roles in industry... What?? I might as well say, "atoms serve many important roles in making my food tasty...

At risk of saying something twice, since just about everything in the normal world is made of atoms, there's no more hope of having readable subsections of this type than having the same sections where the word "matter" takes the place of "atoms." If you can't write a bit on "role of matter in industry" or "role of matter in chemistry" then you shouldn't try to do what's attempted here.

Is anything at all to be done? I've suggested limiting discussion to places where SINGLE atoms are used to do some task. That, at least, has some hope of limitation to paragraph or subarticle size.Steve 14:07, 30 June 2006 (UTC)

I don't think you need to worry too much about this. The state of the article is much improved from its disastrous state a year ago. Nobody really intends to put in an "atoms in industry" section at this point. -- Xerxes 18:07, 30 June 2006 (UTC)

There's a whole lot of unimportant nonsense in this article, and just plain untruths.... (above by anon. 67.124.223.202 )

agreed - I removed the whole section below for discussion. Parts seem to be written for a 4th grader - others are simple nonsense ...

==Atoms in the universe and our world==

Using inflation theory, the number of atoms in the observable universe can be estimated to be between 4×10⁷⁸ and 6×10⁷⁹. However, because of the possibly infinite nature of the universe, the total number of atoms in the entire universe may be much larger or even infinite. This does not change the estimated number of atoms in the observable universe since that is the number of atoms within about 14 billion light years of us - which is all that we can observe since the universe is only about 14 billion years old.

===Atoms in industry===

Atoms serve many important roles in industry, including in nuclear power plants, industrial materials science, and many roles in the chemical industry.

===Atoms in science===

The study of atoms has been a major focus of scientific research for decades. Atomic theory has wide-ranging impact on many fields of science, including nuclear physics, spectroscopy, and all of chemistry, among many other topics. Today, most scientific research associated with atoms is in the field of quantum mechanics. Subatomic particle research is also a popular field.

The study of atoms was done by largely indirect means through the 19th century and early 20th century. In recent years, however, new techniques have made the identification and study of atoms easier and more accurate. The electron microscope, invented in 1931, has allowed pictures to be taken of actual, individual atoms. Methods also exist to identify atoms and compounds. Mass spectrometry methods allow the exact identification of the types and amounts of atoms in a substance. GCMS is often used by forensics investigators to identify unknown substances. X-ray crystallography reveals the structure of certain atomic and molecular substances.

The whole section seems to be written just to fit a prescribed format, it doesn't work - most is simple absurdity as the anon mentioned above. Forget the prescribed format and write meaningful prose - not shoehorned nonsense. Vsmith 12:59, 26 July 2005 (UTC)

The last paragraph above re: the study... is the only bit worth re-inserting as is or modified. Vsmith 13:06, 26 July 2005 (UTC)

OK, I've re-inserted the Study of paragraph into the History of atoms section - seems to fit there. Vsmith 14:06, 26 July 2005 (UTC)

The diagram is the Bohr model of the atom, which is widely regarded as incorrect, and should be deleted from this page.

Disputed

DISPUTED:

20:48, 3 December 2005 Xerxes314 m (revert irrelevant addition; quarks play no part in atomic theory)

Since when do quarks play no part in current atomic theory? Are we still in third grade? I've added information--one sentence--that quarks and leptons make up atoms. Give me a good reason why quarks are not a part of the atom. Atomic theory should not be based on strictly pre-1925 physics. And how about a real image of an atom -- not based on the Rutherford model from 1911, perhaps like the one below? And how about stating that the electron has a wave-particle duality and doesn't look like a planet in orbit? Can we stop teaching atomic theory as it existed 100 years ago and begin to teach the atom as we know it today?

Hydrogen atom

Voyajer 01:34, 11 December 2005 (UTC)

Also, considering that my edits get erased in favor of outdated data, I'd like to add the following facts to the article if there are no objections: 1. In models of the Big Bang, Big Bang Nucleosynthesis predicts that within one to three minutes of the Big Bang all the current atomic material in the universe was created producing no heavier element than lithium, but mostly hydrogen and helium. However, atoms could not form in the intense heat. 2. Big Bang chronology of the atom continues to approximately 379,000 years after the Big Bang when the cosmic temperature had dropped to just 3,000 K which allowed the first atoms to form. It was then cool enough to allow protons to capture one electron each and form neutral atoms of hydrogen. Hydrogen makes up approximately 75% of the atoms in the universe. Helium makes up 24% and all other elements make up 1%. 3. Since the size of the universe is unknown, the total numbers of atoms in the universe is unknown, but the number is not thought to be infinite because current theory suggests we live in a finite universe. 4. The only thing that can be known about atoms in the universe is that the nucleus of atoms, that is the protons and neutrons, which are baryons (except that this appears to be unacceptable terminology by the main writers working on this article)... At any rate, the electron (a type of lepton) is not significantly massive compared to the baryons. One thing we can say about the mass of the baryons in the universe, meaning the mass of the protons and neutrons, is that we can tell what the ratio of their density ought to be from the Big Bang model. Big Bang Nucleosynthesis predicts that 1/20 of the total mass of the Universe is baryonic matter. However, from the density we can see through telescopes of matter in regions of the visible universe, 99% of the baryons are missing. This has given rise to theories of dark matter (also made of baryons--or if you prefer atoms) to make up the difference. What that means is that there are probably more atoms out there than we can see through our usual means of detection. In other words, we cannot see visible light from these atoms nor can we detect electromagnetic radiation, but they exist. (According to the latest issue of Discover magazine 12/05, a dark galaxy named Virgo H121 has been detected by radiowave detectors. Otherwise, it is invisible in telescopes.)

There is obviously a lot more information on the atom that could be introduced into the article, but I don't see how that is possible when people here are arguing against quarks being part of the atom. It seems useless to talk about neutrinos or any other atomic particles with this strong adherence to archaic models of the atom.

Voyajer 05:52, 11 December 2005 (UTC)

Moved comment to page bottom.

Also removed ugly disputed tag from article, the cleanup tag is adequate. Wikilinked quark & lepton. I don't think we need a treatise on atomic physics and cosmology in this introductory article. I do agree there is room for improvement though. And the image is representative of the Bohr model, not Rutherfords, qm images are further down in the article. The Bohr image contains more info than your hydrogen atom image, but the image and its limitations should be referred to/explained in the text. Vsmith 15:18, 11 December 2005 (UTC)

Actually, the problem with the Bohr atom is that it does not represent the atom as we know it today. It teaches everyone that atoms look like miniature solar systems. This concept is so wrong. Even an 8-year-old can get the concept of the real picture of the atom as we know it today if you give them a real picture of an atom. The Bohr atom model is only useful when you can show an animation of quantum leaps. Otherwise, it is a model from 1915 of the atom. It went out of atomic theory in 1925. We are teaching the world the wrong thing. Atoms are not like miniature solar systems. Also, just because you claim this is "an introductory article" doesn't mean it should give false information about the structure of the atom. The helium atom in ground state is pictured below. It is a conceptualization of two electrons in the same s orbital which is allowed. It gives all the information of the antiquated and fallacious model of the Bohr atom, but in terms of real modern physics. Bohr himself did not believe in the Bohr atom after 1925. It is just as bad as drawing a picture of an earth centered universe like Ptolemy and saying that no one could understand a picture of the sun centered solar system. It is equally ludicrous to teach the ancient Bohr model of the atom as much as teaching an earth-centered solar system. I have added the correct visualization.

Helium atom

Voyajer 18:03, 11 December 2005 (UTC)

There are two important principles that make quarks irrelevant to atomic physics: confinement and the renormalization group. The former tells us that the strong interaction is irrelevant at scales outside 1fm; atoms have sizes on the order of Angstroms. The latter tells us that for many systems, degrees of freedom that are important at high energies become irrelevant at low energy, where the systems are much better described by effective theories. In this case, atomic models only take into account at first-order the total charge and mass of the nucleus. This hardly even takes us to the level of the nucleons, much less quarks. -- Xerxes 16:00, 12 December 2005 (UTC)

Xerxes314: Yes, point taken. I also do not believe the article should contain sophisticated particle physics, but the properties of quarks do not preclude them from being described in the structure of the atom. In fact, no other major encyclopedia dismisses the idea of quarks from their articles on the "atom" upon the grounds you propose. For instance, the Encyclopedia Britannica in its first section on atom composition says:

"Even the individual protons and neutrons that make up the nucleus have an internal structure of their own. The constituents of nucleons are called quarks. Unlike the particles composing the larger units of matter, the quark cannot be freed from the nucleon and studied in isolation. The strong force acting between quarks is so powerful that they can never be completely separated. Any attempt to probe the substructure of a nucleon releases particles of various types, but the particles produced contain quarks in fixed combinations, never single quarks. Particles containing quarks are collectively called hadrons. Hadrons are classified into two categories: baryons and mesons. Baryons, which are composed of three quarks, include protons and neutrons as their lightest examples. Mesons, which contain two quarks, are largely responsible for nuclear forces. Except for the nucleons, all such particles decay in a small fraction of a second after their creation."

MSN Encarta online says in its introductory article on the "atom":

"Unlike electrons, which are fundamental particles, protons and neutrons are made up of other, smaller particles called quarks. Physicists know of six different quarks. Neutrons and protons are made up of up quarks and down quarks—two of the six different kinds of quarks. The fanciful names of quarks have nothing to do with their properties; the names are simply labels to distinguish one quark from another." http://encarta.msn.com/encyclopedia_761567432/Atom.html

I think it is or should be the goal of Wikipedia to match the most respected encyclopedias in integrity and content.--Voyajer 04:12, 13 December 2005 (UTC)

Ions & Elements

There have been many good changes to the article today made by User:Voyajer. However, the sentences about ions & about elements contribute to defining the limits of what counts as an atom. What counts as an atom is not just what particles it consists of, but that it be the smallest particle of an element. The contrast with ions helps make clear what, striclty speaking, does not count as an atom --JimWae 05:08, 12 December 2005 (UTC)

You have commented twice now about what most matter in the universe is - but nowhere have I stated anything about that. My point is that "atoms" that are not neutral, strictly speaking, go by another name - ions - although, of course, it is not a distinction always made.--JimWae 08:48, 12 December 2005 (UTC)

There is really too much detail in lead about what subatomic particles are made of. The lead is an introduction to the article - yet the article itself never mentions quarks nor leptons. Topics are not supposed to be most fully developed in the introduction--JimWae 08:48, 12 December 2005 (UTC)

I totally agree with you on this one and it is my fault for putting the idea of quarks and leptons in the introduction. I will think about how to better introduce them into the text.

Also, what I meant about what "most of the matter in the universe is" is that you seemed to imply in saying "strictly speaking" that most atoms were in their neutral state. The wording "strictly speaking" wasn't making sense to me. However, I really like the way the paragraphs that you have added have evolved and I think they now do belong in the introduction. After all, this article has evolved from a team effort and I've mostly just organized it a bit. I appreciate your keeping track of my additions and omissions. Voyajer 00:58, 13 December 2005 (UTC)