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This is purely theoretical question. Moreover, I am not a physicist, so I may write some stupid things. I'm sorry.

Back to the topic: I have heard about radioactive decay. Basically after some (sometimes long) period of time, half of atoms decay into lesser atoms, and some of the energy is released as a side effect.

This got me thinking - let's say that I have honey closed in some perfectly isolated container - I guess that's called the Isolated system. After some time, honey will eventually decay, and energy will be released. More and more energy will be released as time passes. Would the temperature increase as the result, or do I lack basic physics?

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    $\begingroup$ I just have to ask, why honey? Why not something notoriously radioactive, just wondering? Thanks $\endgroup$ – user81619 Sep 25 '15 at 22:44
  • $\begingroup$ @count_to_10 I know. Something radioactive would be probably much easier, since it decays quickly. But since it got me thinking after I was putting some honey to my tea; its properties that allow it to be edible even after long time. I could have changed it, but I thought that there's little difference. Also, I think that honey's more intriguing ;) $\endgroup$ – MatthewRock Sep 25 '15 at 23:12
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    $\begingroup$ For most "normal" things, the heat will dissipate far faster than it's created during radioactive decay. If you create a perfectly closed system, which might be impossible, but if you do it somehow, then almost all food will emit some radiation and generate some heat through carbon-14 and some food by Potassium-40 but those are trace elements and the decay is very slow. The heat increase would be very very very gradual. Bananas have on rare occasion set of radiation detectors. $\endgroup$ – userLTK Sep 25 '15 at 23:33
  • $\begingroup$ @userLTK I am aware that it's a slow process. I'm aware that it's probably impossible to create isolated system. But I take it as a thought experiment, which might teach me a thing or two, instead of a practical question(It's not like I'm going to hide honey in isolated system and I'm worried about it's nutritious values). $\endgroup$ – MatthewRock Sep 25 '15 at 23:39
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    $\begingroup$ @userLTK "nutritional risk" -- aside from toxins generated by invading microbes :-) $\endgroup$ – Carl Witthoft Sep 26 '15 at 11:54
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After some time, honey will eventually decay

The vast majority of the atoms in most honey are not radioactive, and will not decay no matter how long you wait. For example, about 1 or 1.5 atoms per $10^{12}$ of the carbon atoms in honey will be $^{14}C$, so you will be getting virtually no heat out of their decay (certainly far less than the heat leaked through your inevitably imperfect insulation).

It's possible that there may be some chemical decay, but honey is quite stable, and its chemical decay could be endothermic for all we know. Another possibility is heat released by microorganisms eating the honey, but most microorganisms don't grow in honey.

However, since honey is a supersaturated sugar solution at room temperature, given time it will crystallize. That crystallization will indeed be exothermic, releasing heat and raising the temperature.

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The short answer is that, in a perfectly insulating container, yes, there might be some heat given off by radioactive decay. Radioactivity and radioactive decay give off "potential energy" that was stored in nuclear bonds. Chemically, two atoms can combine together due to electric forces and quantum effects to form a compound (sometimes releasing energy because the bond is more stable than the free atoms, sometimes storing energy in the bond). The nuclear energy is basically the same thing, but it's caused by the 'bonding' of protons and neutrons into heavier nuclei with something call the "strong nuclear force." This force overcomes to repulsion from the electric force on two positive protons at short distances and glues them together and it's still not fully understood by physicists today. Light atomic nuclei, like most of the ones in honey, give off energy when they bond and are therefore very stable. On the other hand, very heavy atomic nuclei - like very 'complex', unstable molecules - take excess energy to create. Plutonium and Uranium are two of the most famous examples, and even 'light' atomic nuclei like Iron are usually only made in very high energy events like supernovas (exploding stars). Sometimes, you also get unstable lighter elements when there are extra neutrons inside the nucleus. These are what are called different isotopes, and a 'heavy' isotope of carbon might decay in honey.

So , indeed technically there is some radioactive decay in honey. However, there are caveats, of course. Honey has a very long shelf life, but I suspect that the decay of the honey's chemical bonds would create more heat than the decay of its atoms. I am not a chemist, though, so I don't know much about the stability of these compounds. Additionally, as others have said, in any sort of 'realistic' environment or experiment, the amount of radioactive decay would be so low that they heat would dissipate and the change would be almost unnoticeable. Maybe on some far away planet there is "uranium honey" or "Radium honey" that does have more radioactive decay.

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