Template talk:Infobox neodymium
Latest comment: 5 years ago by ComplexRational in topic Nd-148 and Nd-150
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Nd-148 and Nd-150
editAccording to JEFF 3.11, the half life of neodymium 148 is 2.7e18 years; it's not stable.
The half life of neodymium 150 is 21e18 years. [1] sign for IP IP -DePiep (talk) 07:54, 7 October 2019 (UTC)
- Pinging @ComplexRational: Double sharp (talk) 10:46, 7 October 2019 (UTC)
- NUBASE 2016[1] pdf says (p. 64): "148Nd Stable (>3.0 Ey)". Our Isotopes_of_neodymium#List_of_isotopes says: "observationally stable". 150Nd: 8.2 Ey. -DePiep (talk) 11:00, 7 October 2019 (UTC)
- I would second that. All sources I find, even the most recent ones, list 148Nd as (observationally) stable with only this lower limit for its half-life. 97.93.121.138, perhaps this is the value you saw (an estimate, not an actually measured half-life)? ComplexRational (talk) 20:56, 7 October 2019 (UTC)
- reply OP: I don't know. Do we need a separate "observationaly stable" option in the infoboxes? IMO too much detail. 1 Ey = 1×1018 y. Age of the Earth is 4.5×109 y (that's 0.0000000045 Ey then, right?). In this Np case, more easy. Also, I have read something like "theoretical calculation" in this. (LOL: this being about Earth age, I thought "Ey" meant "1×Earth age". It is like O(1×109)× Earth age). -DePiep (talk) 21:17, 7 October 2019 (UTC)
- @DePiep: I don't think that is necessary, for it quickly becomes too complicated to distinguish different cases. Stable or unstable is enough detail for the infobox; the article text can explain the rest if necessary. ComplexRational (talk) 21:01, 8 October 2019 (UTC)
- OK. no "observed stable" in our reduced tables. (nothing about the Big Isotopes Table). -DePiep (talk) 21:05, 8 October 2019 (UTC)
- (edit conflict) @DePiep: I agree. If it is stable, or unstable, we say so; this is not the place for the predictions. When we discover something that we thought was stable actually decays like we did for 78Kr, we'll change it. Double sharp (talk) 21:06, 8 October 2019 (UTC)
- @DePiep: I don't think that is necessary, for it quickly becomes too complicated to distinguish different cases. Stable or unstable is enough detail for the infobox; the article text can explain the rest if necessary. ComplexRational (talk) 21:01, 8 October 2019 (UTC)
- reply OP: I don't know. Do we need a separate "observationaly stable" option in the infoboxes? IMO too much detail. 1 Ey = 1×1018 y. Age of the Earth is 4.5×109 y (that's 0.0000000045 Ey then, right?). In this Np case, more easy. Also, I have read something like "theoretical calculation" in this. (LOL: this being about Earth age, I thought "Ey" meant "1×Earth age". It is like O(1×109)× Earth age). -DePiep (talk) 21:17, 7 October 2019 (UTC)
- I would second that. All sources I find, even the most recent ones, list 148Nd as (observationally) stable with only this lower limit for its half-life. 97.93.121.138, perhaps this is the value you saw (an estimate, not an actually measured half-life)? ComplexRational (talk) 20:56, 7 October 2019 (UTC)
- NUBASE 2016[1] pdf says (p. 64): "148Nd Stable (>3.0 Ey)". Our Isotopes_of_neodymium#List_of_isotopes says: "observationally stable". 150Nd: 8.2 Ey. -DePiep (talk) 11:00, 7 October 2019 (UTC)
- eh, let me re-question the OP: what is the age to say "this is stable"? (Don't know about other isotopes, this one's age looks safe). Asking for the Big Table—reduced tables. -DePiep (talk) 21:14, 8 October 2019 (UTC)
- @DePiep: There shouldn't be any, given the really long half-life of 128Te. The standard we have been using is: if we have seen a decay, we know a half-life, so it goes in. If we haven't seen a decay, it's stable for the infoboxes and possibly observationally stable for the main "isotopes of X" articles. Double sharp (talk) 06:15, 9 October 2019 (UTC)
- Exactly, we say a nuclide is (observationally) stable unless decay is observed. But, Double sharp, it's still not clear when we say "stable" or "observationally stable": some nuclides have lower limits established or clear predictions, whereas others are shown to be theoretically unstable by calculating energy release (from values given in NUBASE) but have not been explicitly predicted as unstable. ComplexRational (talk) 15:01, 9 October 2019 (UTC)
- @DePiep: There shouldn't be any, given the really long half-life of 128Te. The standard we have been using is: if we have seen a decay, we know a half-life, so it goes in. If we haven't seen a decay, it's stable for the infoboxes and possibly observationally stable for the main "isotopes of X" articles. Double sharp (talk) 06:15, 9 October 2019 (UTC)
References
- ^ Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001.