Talk:Atomic nucleus

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[edit] Atomic Decay

If a nucleus has too few or too many neutrons it may be unstable, and will decay after some period of time. For example, nitrogen-16 atoms (7 protons, 9 neutrons) alpha decay to cadmium-48 atoms (24 protons, 24 neutrons) within a few minutes of being created. In this decay a neutron in the nitrogen nucleus is turned into a proton and an electron by the weak nuclear force. The element of the atom changes because while it previously had seven protons (which makes it nitrogen) it now has eight (which makes it oxygen). Many elements have multiple isotopes which are stable for weeks, years, or even billions of years.

Alpha decay and cadmium-48 atom? That is too ridiculous. Someone please fix it.

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This page, like many of our science pages, suffers from the terrible flaw of being peppered with much scientific jargon that is not adequately explained. For example, observe the following paragraphs:

A heavy nucleus can contain hundreds of nucleons (neutrons and protons), which means that to some approximation it can be treated as a classical system, rather than a quantum-mechanical one. In the resulting liquid-drop model, the nucleus has an energy which arises partly from surface tension and partly from electrical repulsion of the protons. The liquid-drop model is able to reproduce many features of nuclei, including the general trend of binding energy with respect to mass number, as well as the phenomenon of nuclear fission.

Here, the editors do not make clear what a classical system is and what a quantum-mechanical one is. This would be bad enough, but the editors then go on to build off that confusing dichotomy, referring to the "resulting liquid-drop model." Since the reader has no idea what a classical or quantum-mechanical system is, the reader cannot even begin to grasp what a liquid-drop model might be, if the author had even bothered to explain what the fucking model was, or how it resulted from the ability to approximate a q/m system as a classical one.

Superimposed on this classical picture, however, are quantum-mechanical effects, which can be described using the nuclear shell model, developed in large part by Maria Goeppert-Mayer. Nuclei with certain numbers of neutrons and protons (the magic numbers 2, 8, 20, 50, 82, 126, ...) are particularly stable, because their shells are filled.

Here, the editors might have redeemed themselves by explaining something about quantum-mechanical effects. They at least mention a nuclear shell model, but then, infuriatingly, leave it at that. They do, however, go on to explain what this nuclear shell model implies, now leaving us totally in the dark, and chewing on ourselves in frustration.

Since some nuclei are more stable than others, it follows that energy can be released by nuclear reactions.

Finally, the editors continually make deductions that are not obvious to the reader, and don't bother to explain how they, or any physicist, arrived at them.

This is not a problem merely with this article: it exists in many others. Our articles are only useful as encyclopedia articles if they are penetrable to the layman.

As a conclusion to this general rant, could someone knowledgable about the physics of atomic nuclei clarify these points? Graft

I don't see a problem with using jargon. In fact, the jargon is an aid to understanding because the meanings are very precise. However, when jargon is used, there need to be links to articles explaining the concepts. I've added a bunch of links to this article, so it should be easier for a reader without any education in science to follow.

To use the existing example, if one doesn't know what surface tension is, then the liquid-drop model may not be obvious. Hence, a link to surface tension was needed.

Material replaced.

Helium was formed from hydrogen in nuclear reactions shortly after the Big Bang, while all the other elements in the universe were created in supernova explosions.

                                    Rednblu 13:23 20 Jul 2003 (UTC)

Many other places in this article need fixing, for example the last paragraph. Rednblu 13:49 20 Jul 2003 (UTC)

[edit] How big?

Please tell me what the size of a nucleus is? No comsmogony until basic material, cheers.

[edit] Nuclear Fission

A changed the section a bit and removed the text about alpha and beta decay. I think it belongs in the Nuclear Decay section. Zarniwoot 00:35, 23 January 2006 (UTC)

[edit] Bohr atom

Since a Bohr atom is not a realistic model, can the picture go? There're lots of problems: Electrons as particles in orbits is wrong, the electrons are too big, and the space occupied by nucleus in the atom unrealistic. Olin 03:32, 29 March 2006 (UTC)

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.

The image I proposed for the atom article is available. Suggestions are still welcomed for improving it. The main problem, of course, is how to make an interesting picture of something that is spherically symmetric and essentially homogeneous. -- Xerxes 15:59, 29 March 2006 (UTC)

[edit] fm unit for size of nucleus

In the first paragraph it stats the size of the nucleus in the unit fm. Clicking on fm merely takes you to the disambiguation page for fm. Should it not take you to the actual page for the unit? Or perhaps the unit should be stated not in it's short form. I think it may be confusing to someone who is not a scientist. —The preceding unsigned comment was added by 24.150.203.74 (talk) 21:57, 7 March 2007 (UTC).

Yup, links to disambiguation pages are stupid. Fixed. However, since it's defined in the page (10^-15 m), perhaps the link isn't needed at all? --Gmarsden 18:18, 8 March 2007 (UTC)