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I know that solid water (ice) sublimes ("evaporates" straight from solid to dissolved gas) in air. On the other hand, some metal objects seem to last forever (e.g. gold, stainless steel and other metals that don't tarnish, rust, etc.) So, does solid metal sublime? And if not, why not, darn it!

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    $\begingroup$ Why a down vote? This seems to be a reasonable question? $\endgroup$ – mmesser314 Apr 23 '15 at 13:13
  • $\begingroup$ I don't know enough about this to write a full answer, but I know from working with vacuum chambers that zinc sublimes in low pressure environments. $\endgroup$ – DanielSank Jul 31 '16 at 18:07
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They do actually, but in normal conditions you can not observe this. The sublimation rate will depend on temperature and energy of sublimation, which is different for different metals. Also in normal conditions you will have some kind of equilibrium - some of the particles that leave the surface will condensate back. But in vacuum techniques you need to take this to account - there are metals with low sublimation energy - such as Zinc, Magnesium, Cadmium e.t.c. You can see them here, here, for example, in the list of non-suitable for vacuum equipment. As an extreme case you can imagine a piece of metal, which is heated from inside and put into deep space, if its mass is small and gravitation attraction can be neglected, it will evaporate.

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You can look up vapor pressure tables charts on the web: vapor pressure chart (Sorry, it's a link to a company page, but I couldn't find a reasonable free resource with a nice layout. Wikipedia does not seem to provide nice charts.)

Typical metals will sublimate at higher temperatures, which is why you don't observe it under regular conditions. Furthermore, at least some of them would start to react with oxygen. To get the proper evaporation behavior, you would need to perform the experiment in vacuum. See the answer by @Ilya.

There is also a metal, which evaporates at room temperature, namely mercury. I'm not sure, show long it would take for one droplet to evaporate, but it does give a significant vapor pressure. On the other hand, it's not sublimation as this is a transition from liquid to vapor. Just wanted to give this as an additional example.

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  • $\begingroup$ Mercury is a liquid at room temperature, so it's boiling, not sublimating. $\endgroup$ – Jerry Schirmer Apr 23 '15 at 12:32
  • $\begingroup$ This is exactly, what I wrote in my answer. $\endgroup$ – engineer Apr 23 '15 at 12:33
  • $\begingroup$ @JerrySchirmer Water evaporates at room temperature without boiling. Boiling water simply evaporates much faster. $\endgroup$ – CJ Dennis May 2 '15 at 11:33

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