Talk:Alpha process

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Contradiction[edit]

Alpha elements are Z >22: (C,O), Ne, Mg, Si, S, Ar, Ca, (Ti).

Neon is Z = 10. C is Z = 6. So what does "Alpha element" mean? I'll make a survey, so this statement can be replaced by something coherent. Said: Rursus ☻ 15:32, 21 November 2007 (UTC)[reply]

Preliminary survey:

N, O, Mg, Ca, Na, Ne, S, Si, Ti (Z ≤ 22) - alpha elements,

Cr, Mn, Fe, Co, Ni, Cu, Zn (Z > 22) - Fe-peak elements.

Said: Rursus ☻ 15:52, 21 November 2007 (UTC)[reply]

As noted below, N and Na aren't alpha-elements. Alpha-elements need their principal isotope to have N = Z and Z even, up to a maximum of about Z = 20. That is, the content of the nucleus is the same as an integer number of alpha particles. Both N and Na have odd Z. Beyond Z = 20 nuclei with N = Z are not stable. Even though 44Ti isn't stable, Ti still "behaves" like an alpha-element in galactic chemical evolution and is usually included in the alpha-element bin because of this. BSVulturis (talk) 19:59, 5 January 2011 (UTC)[reply]

The sequence of A=2Z elements up to Z=22 is as follows including (earth constituency percentages): 2He4 (99.98, 4Be8 (Zero unstable Alpha emitter), 6C12 (98.9), 8O16 (99.76), 10Ne20 (90.48), 12Mg24 (78.99), 14Si28 (92.93), 16S32 (95.02), 18Ar36 (0.337), 20Ca40 (96.94), and 22Ti44 (zero unstable Alpha emitter). It wouldn't include 7N14.WFPM (talk) 19:28, 6 September 2009 (UTC) So we have the proposition that (with the exception of 1H1) most of the major constituents of the even Z numbered elements up to Z=20 are of the type A=2Z, except for 4Be8, which is unstable, and 18Ar36, which has been depleted from the earth.WFPM (talk) 21:25, 6 September 2009 (UTC)In stars, the ability of the smaller A=2Z atoms to be combined into the larger A=2Z atoms is described in the article Triple-alpha process.[reply]

Error[edit]

At the end of the article is stated that are SNe II that produces alpha elements and SN Ia that produces iron peak elements. This is not right, actually is the opposite. SNe II are so called core-collapse SNe. The progenitors of these SNe are massive star (from 8 to 40 solar masses). These stars are able to synthesize all elements up to ⁵⁶Fe (the iron-peak elements). Sn Ia are white dwarfs. The progetitors are low mass stars that can synthsize elements up to C. During the exlposion they sinthesize alpha elements ^[1]

References

^ Mo, Houjun (2010). Galaxy formation and evolution. Cambridge. ISBN 9780521857932.

Recent edit by IP 76.64.115.46.[edit]

I am concerned about recent edits by IP 76.64.115.46. I originally simply corrected some usage errors of English, but noticed that many (or all) of the nuclei synthesis equations were also changed by this IP editor. I do not know myself what is the correct representation of these equations. Can someone knowledgeable check this out and correct/revert if necessary? 173.48.62.104 (talk) 03:47, 5 November 2015 (UTC)[reply]

Wiki Education assignment: Biogeochemical Cycles[edit]

This article was the subject of a Wiki Education Foundation-supported course assignment, between 11 January 2023 and 21 April 2023. Further details are available on the course page. Student editor(s): MH0706 (article contribs). Peer reviewers: Fgraba.

— Assignment last updated by MethanoJen (talk) 20:04, 13 January 2023 (UTC)[reply]

Hello, I am a graduate student at Georgia Institute of Technology and will be helping to improve this article as part of the course mentioned above. I'm new to this page so I welcome any advice, comments, or feedback on edits I make! Thanks, MH0706 (talk) 19:09, 17 February 2023 (UTC)[reply]

[1] Mo, Houjun (2010). Galaxy formation and evolution. Cambridge. ISBN 9780521857932.

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