Timeline for Why does the metastable form of Technetium-95 have a longer half-life than its most stable state?
Current License: CC BY-SA 3.0
14 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 7, 2013 at 14:36 | vote | accept | Jivlain | ||
| Apr 28, 2013 at 16:44 | history | edited | Manishearth | CC BY-SA 3.0 |
deleted 6 characters in body
|
| Apr 28, 2013 at 5:49 | history | migrated | from chemistry.stackexchange.com (revisions) | ||
| Apr 28, 2013 at 5:49 | comment | added | Manishearth | @Jivlain: Great, moving :) | |
| Apr 28, 2013 at 2:48 | comment | added | Jivlain | @ManishEarth: I have no particular objections. Several seem to think that a move would be beneficial, so go ahead. | |
| Apr 27, 2013 at 7:52 | comment | added | Manishearth | Jivlain: Would you like this to be migrated to Physics? (don't cross post, just reply to me in a comment) | |
| Apr 27, 2013 at 7:52 | comment | added | Manishearth | @RichardTerrett: No need to be so formal, we're all friends here :) The general rule is that we only migrate if (a) The post is off topic (b) the OP asks, or (c) a good answer is not received. I'll wait a while first for the OP to chime in (or for answers to come in), and then migrate if necessary. | |
| Apr 27, 2013 at 5:44 | comment | added | Richard Terrett | @ManishEarth, BenNorris - I respectfully submit that nuclear isomerism is far more nuclear physics than chemistry, taking place on energy and length scales orders of magnitude removed from chemical processes and not involving electronic structure. I've only ever seen it discussed in chemistry in the context of understanding Mössbauer spectroscopy. Whilst I apologise for being a bit presumptuous, I do think this question would attract a greater breadth and depth of answers on the physics site. | |
| Apr 26, 2013 at 11:31 | comment | added | Ben Norris | This question is probably on topic on Chemistry and Physics. Nuclear transformations, radioactivity, fusion, and fission are covered in most general chemistry books. Let's leave this one for awhile and migrate it only if it does not seem to be getting the appropriate attention. | |
| Apr 26, 2013 at 7:06 | comment | added | Manishearth | @RichardTerrett: I can, but isn't this on topic on Chem as well? I thought we allow questions about nuclei.. | |
| Apr 26, 2013 at 4:44 | answer | added | Nicolau Saker Neto | timeline score: 3 | |
| Apr 26, 2013 at 3:45 | comment | added | Nicolau Saker Neto | A very interesting case is $^{180m}Ta$, where the metastable isomer has a half-life much longer than the current age of the Universe, and is in fact the only naturally occurring excited nucleus. More information is available at this wiki article. | |
| Apr 26, 2013 at 3:07 | comment | added | Richard Terrett | Hopefully a moderator can shift this to phys.SE. Just surfing around tables of isotopes does however reveal that isomers that are longer-lived than their ground states are not uncommon (102mTc, 116mCs, etc.). Anyhow, this looks like another application of the difference between thermodynamic and kinetic stability. Intuitively, the decay pathways that lead to rapid decay of a ground-state isotope are less probable (maybe totally impossible) in an isomer. The isomer, whilst less thermodynamically stable, is stuck in a potential energy rut that it can only escape through slow processes. | |
| Apr 25, 2013 at 14:51 | history | asked | Jivlain | CC BY-SA 3.0 |