Editing Sublimation (phase transition) (section)

{{Short description|Transition from solid to gas}}
{{Redirect|Sublimates||Sublimation (disambiguation){{!}}Sublimation}}
{{distinguish|subliminal stimuli}}
{{pp|small=yes}}
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READ BEFORE EDIT, sublimation refers to ALL THREE CASES:
1. Sublime gradually: below triple point and left of solid-gas boundary
(similar to evaporation)
(bottom left of solid in phase diagram)
2. Sublime rapidly: below triple point and at solid-gas boundary
(similar to boiling)
3. Sublime gradually: above triple point and left of solid-liquid boundary (yes, solid sublimes above triple point)
(also similar to evaporation, just higher pressure)
(top left of solid in phase diagram)
These three cases jointly exhaust the solid space in the phrase diagram. This makes sense, after all, technically, all solids sublime (depending mostly on vapour pressure, which is very situational).
One may notice there is a fourth case in the solid space, that is, at the solid-liquid boundary. It is uncertain if the solid is still defined as subliming WHILE melting, and in case it is, it would be subliming rapidly.
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checking some online English dictionaries:
1. sublime and sublimate are both valid, and both have some other meanings
https://www.merriam-webster.com/dictionary/sublime#did-you-know
(also almost every dictionary)
2. sublimate may mean the product
https://www.merriam-webster.com/dictionary/sublimate#dictionary-entry-2
https://www.collinsdictionary.com/dictionary/english/sublimate
https://www.dictionary.com/browse/sublimate
https://chambers.co.uk/search/?query=sublimate&title=21st
https://www.wordreference.com/definition/sublimate
3. sublimation may also mean itself followed by deposition
https://www.collinsdictionary.com/dictionary/english/sublime
https://www.dictionary.com/browse/sublime
4. sublimation seems used to mean deposition alone but this meaning is now completely obsolete, few if any online dictionary has such meaning as of 2023, the archaic use is likely phased out
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[[File:Nickelocen an einem Kühlfinger.jpg|thumb|right|Dark green [[crystals]] of [[nickelocene]], sublimed and freshly deposited on a [[cold finger]]]]
[[File:Sublimation of iodine.webm|thumb|Sublimation of [[iodine]]]]

'''Sublimation''' is the [[Phase transition|transition of a substance]] directly from the [[solid]] to the [[gas]] state, without passing through the [[liquid]] state.<ref>{{cite book |last1=Whitten |first1=Kenneth W. |last2=Gailey |first2=Kenneth D. |last3=Davis |first3=Raymond E. |title=General chemistry |url=https://archive.org/details/generalchemistry00whit_0 |url-access=registration |date=1992 |publisher=Saunders College Publishing |isbn=0-03-072373-6 |page=[https://archive.org/details/generalchemistry00whit_0/page/475 475] |edition=4th}}</ref> The verb form of sublimation is ''sublime'', or less preferably, ''sublimate''.<ref name=":0">{{cite Merriam-Webster|Sublimate}}</ref> ''Sublimate'' also refers to the product obtained by sublimation.<ref name=":0" /><ref>[https://www.collinsdictionary.com/dictionary/english/sublimate "Sublimate"]. [[Collins English Dictionary#CollinsDictionary.com|CollinsDictionary.com Dictionary]].</ref> The point at which sublimation occurs rapidly (for further details, see [[#False correspondence with vaporization|below]]) is called critical sublimation point, or simply sublimation point. Notable examples include sublimation of [[dry ice]] at room temperature and atmospheric pressure, and that of solid [[iodine]] with heating.

The reverse process of sublimation is [[deposition (phase transition)|''deposition'']] (also called ''desublimation''), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state.<ref name="DepositionDef">{{cite journal |title=Controlling condensation and frost growth with chemical micropatterns |first1=Jonathan B. |last1=Boreyko |first2=Ryan R. |last2=Hansen |first3=Kevin R. |last3=Murphy |first4=Saurabh |last4=Nath |first5=Scott T. |last5=Retterer |first6=C. Patrick |last6=Collier |journal=Scientific Reports |year=2016 |volume=6 |pages=19131 |doi=10.1038/srep19131 |pmid=26796663 |pmc=4726256 |bibcode=2016NatSR...619131B}}</ref>

Technically, all solids may sublime, though most sublime at extremely low rates  that are hardly detectable under usual conditions. At [[standard conditions for temperature and pressure|normal pressures]], most [[chemical compound]]s and [[chemical element|elements]] possess three different states at different [[temperature]]s. In these cases, the transition from the [[solid]] to the [[gas]] state requires an intermediate liquid state. The pressure referred to is the [[partial pressure|''partial'' pressure]] of the substance, not the ''total'' (e.g. atmospheric) pressure of the entire system. Thus, any solid can sublime if its [[vapour pressure]] is higher than the surrounding partial pressure of the same substance, and in some cases, sublimation occurs at an appreciable rate (e.g. water ice just below 0&nbsp;°C).

For some substances, such as [[carbon]] and [[arsenic]], sublimation from solid state is much more achievable than [[evaporation]] from liquid state and it is difficult to obtain them as liquids. This is because the pressure of their [[triple point]] in its [[phase diagram]] (which corresponds to the lowest pressure at which the substance can exist as a liquid) is very high.

Sublimation is caused by the absorption of heat which provides enough energy for some molecules to overcome the [[intermolecular force|attractive forces]] of their neighbors and escape into the vapor phase. Since the process requires additional energy, sublimation is an [[endothermic]] change. The [[enthalpy of sublimation]] (also called heat of sublimation) can be calculated by adding the [[enthalpy of fusion]] and the [[enthalpy of vaporization]].