Discuter:Nucléide

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[modifier] Nucléide

Discussion rapatriée depuis Discussion_Utilisateur:Duckysmokton#Nucléide

Thank you, Duckysmokton, for the numerous improvements you made to my text. Clearly, French is not my native language, but it is fun to try.

What do you mean by "Référence necéssaire"? This may be the only place where I disagree with your changes. Greetings,HPaul 4 janvier 2007 à 23:29 (CET)

Now, I understand the awful lack of accent :)

Thank you for your contribution.

For the "reference needed" : I was wondering about the stability criteria that you assert to be "having a half-life at least as large as the age of the earth" (seems to be a geology specific criteria). After some googling, I can't find any stability definition related to a precise duration. However, I found:

• here (sorry, (fr)), a nuclide is said to be stable if no radioactivity can be detected with current means of measurement
• analogous in english, here¹ or here : "Isotopes are said to be stable if, when left alone, they show no perceptible tendency to change spontaneously"
• here and in many other documents : "if the nuclear forces between the protons and neutrons are greater than the electric repulsive force of the protons, the nucleus will remain intact and unchanging. In other words, the muclide is said to be stable"

None of these definitions are satisfactory, the half-life length is arbitrary, the lack of perceptible radioactivity depends on the technology (new decaying modes can be discovered, like en:cluster decay), and balanced internal forces does not seems relevant. IMHO, only metastability exists and all the stability criteria are arbitrary and relevant only to their restricted field of concern. We might write something like this in both (fr) & (en) articles. Duckysmokton ^blabla 5 janvier 2007 à 13:30 (CET)

¹: by the way, in this document, p2, there is a great figure explaining isotope/isotone/isobare in the graphical context of the nuclide chart, it should inspire a home-made one in commons.

Hello, Duckysmokton! You are right, of course: whether or not a nuclide is stable, that does not depend on the age of the earth! It is only that a nuclide present at the birth of the earth would no more be present now if it had too short a half-life. Please look at the present version of Nucléide to see if it is better understandable now! Greetings,HPaul 6 janvier 2007 à 22:45 (CET)

That's quite better! Finally, the age of the earth defines what are the natural nuclides, not the stable ones. I'll do some minor changes about the langage and add the isoschmuck figure. Duckysmokton ^blabla 8 janvier 2007 à 13:13 (CET)

Thank you, Duckysmokton. Could you please also improve my translation of

"Before the term nuclide was internationally accepted (ca. 1950), the term "isotope" was also LOOSELY used to describe a nuclear species, i.e., a nuclide."HPaul 10 janvier 2007 à 22:33 (CET)

Voilà c'est fait. Duckysmokton ^blabla 12 janvier 2007 à 13:03 (CET)

C'est fait, et bien fait, merci!HPaul 12 janvier 2007 à 22:16 (CET)

[modifier] Radium

Hello Duckysmokton, I used radium as an example of a shortlived substance present on earth, but you changed it to thorium-234. Why? I prefer radium since it is much better known generally than Th-234. Please change it back! HPaul 16 janvier 2007 à 21:57 (CET)

I did it because ²³⁴Th is the first daughter of the α decay of ²³⁸U and because it is naturally present besides its very short half-time. After checking en:Uranium-238#Radium_series, it appears that ²²⁶Ra is also a far daughter of ²³⁸U.

Personally, I like the aspect of direct relationship between the two examples, but you're right when you say that it lacks of notoriety, all the more than ²³⁴Th is naturally present but in a constant renewal from uranium decay and therefore is not exploitable. I'll return to a radium version tomorrow if you don't do it yourself. Duckysmokton ^blabla 16 janvier 2007 à 23:49 (CET)

C'est fait. HPaul 17 janvier 2007 à 11:24 (CET)