[iScience]

question modified: gaseous ions do not exist in environments like the earth's atmosphere. why is this?

[magician4]

the most simple compound - cation you could possibly think of is the dihydrogen-cation H₂⁺

this one is an example of a compound existant in gas phase, as it is formed by ionising cosmic radiation in huge interstellar hydrogen gas clouds, and can be detected there

so, with all due respect: the whole foundation of your question is ...wrong


regards

Ingo

[magician4]

other than what we've been taught in the beginning ("ions" all around..), for real free ions are something that is very hard to achieve, the energies for charge separation "neutral object  [object]⁺ + e^- " being that high.

Furthermore, to bear a free charge is something, small objects try to avoid due to the high charge density resulting thereof: that's why H⁺ for example in water at least will accommodate 4 water molecules to gain [H₉O₄]⁺ if there are further water molecules to stabilize this "core".
(You wouldn't want to meet a "for real" free H⁺ : the situation coming closest to this might be Olah's super acids, and the H⁺ there easily will attack next to anything that usually is considered to be completely inert to those reactions. For example, methane will swiftly become protonated:
CH₄ + H⁺  [CH₅]⁺  )

So, ions will tend to collect other particles in huge numbers around them, and the aggregates resulting thereof aren't considered "gases" anymore, but "aerosols" instead. (That's how cloud formation is being triggered by cosmic radiation in the lower atmosphere, (on of the reasons discussed) why heavy rain usually is accompanied by lightning, how a cloud chamber works.)

  free ions are "trapped" by neutral molecules, forming huge , non-gaseous aggregates along the way. Those aggregates, after a while, are prone to recombination with their counterparts of opposite charge, should they meet them.
Hence, though "free" charged molecules in the atmosphere are anything but nonexistent, their average concentration is quite low, very very low...
...so, in kind of a generalization we tend to say that they don't exist in the gas phase

regards

Ingo

[408]

magician4 is correct.  This is simply an over generalization that has been taught.  Gaseous ions can exist, they are just uncommon at the temperature and pressure on earth's surface. In a mass spec, gaseous ions of even heavy atoms exist in the gas phase. 

[iScience]

So, ions will tend to collect other particles in huge numbers around them, and the aggregates resulting thereof aren't considered "gases" anymore, but "aerosols" instead. (That's how cloud formation is being triggered by cosmic radiation in the lower atmosphere, (on of the reasons discussed) why heavy rain usually is accompanied by lightning, how a cloud chamber works.)

okay that makes sense, but i thought clouds were formed by condensation nuclei of neutral particulates such as small dust particles or just about any particle around that size?

[magician4]

but i thought clouds were formed by condensation nuclei of neutral particulates such as small dust particles or just about any particle around that size?

this is not completely correct, as in fact the influence of cosmic radiation overrules the factors you've named by far:

people presumed since the late 1940'th that in fact even slightly undersaturated water vapor/air gas mixes might be "triggered" by cosmic radiation to give condensation nucleii for cloud formation.

(charge will attract other water molecules until cloud type aggregates form, even if the air is not yet oversaturated with respect to water vapor, by the mechanism described in my earlier post. These aggregats provide kind of an "umbrella", reflecting on top but shadowing the air/water vapor beneath, hence cooling it, and that's when it really starts to become a cloud)

Final experimental proof for this long standing theory came from the "cloud project" at Cern in the beginning of this year, if memory serves (which still is going on [the project, that is ], for dotting the i's and crossing the t's , esp. in studying the co - influence of additional components like aerosols from airplanes, SO₂/SO₃ , NO_x , smog ... you name it, i.e. "global dimming")

regards

Ingo

[iScience]

i have a UV lamp and every time i turn it on, according to the process you described, should be ionizing compounds in the air which means aerosols should be forming in the air right? the peak wavelength is around 96nm which corresponds to an energy of 2.07e-18J per photon. The dissociation of an H-O bond is 458.9 kJ/mol which is 7.6e-21J. So i should definitely have water dissociating all around my UV lamp. How do i detect it?

[magician4]

to split a covalent bond symmetrically (i.e. generate uncharged radicals , which requires much less energy than forming ions) is an easy task (though even those concentrations mostly are low, and hence difficult to measure)
if you'd irradiate air, water vapor with UV, therefore my best guess is that you'd have some O₃ and H₂O₂ as results of such a process, resulting from oxygen radicals looking for new partners.

however, to generate free ions, i.e split bonds in an ionic way and / or abstract electrons, is something that requires much higher energies, and I doubt that this can be done by simple UV-irradiation in relevant amounts (else, a common UV-beam would generate a cloud trail in the air, wouldn't it?)

Nevertheless, once those ions were formed by whatsoever method, they should be easily detectable by the usual spectroscopic measures , like IR and thatlike (in IR for example , you can easily discriminate CH₃COOH from CH₃COO^- by analyzing the C=O absorption wavenumber )
At least , that's how it's being done in astronomy

regards

Ingo