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Hydrogen atom stripped of an electron

  1. Apr 24, 2015 #1
    What happens if a hydrogen molecule is stripped of an electron? Will it become 2H+ or will it become H and H+?
  2. jcsd
  3. Apr 24, 2015 #2


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    It becomes H II ( pronounced H 2)
    ionised hydrogen is very common in nebula in outer space where the electrons have been stripped off the hydrogen atoms by intense UV light and are very easily detected optically
  4. Apr 24, 2015 #3
    Thank you for clearing that up.

    What electric field strength is needed to remove the final electron from the ionized hydrogen? Im assuming a high enough voltage would strip the last electron an dissociate the hydrogen gas.
  5. Apr 24, 2015 #4


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    You can estimate the needed strength by knowing the second ionization energy. Actually ionization by DC field is almost impossible, either you will want to use electron impact ionization or XUV radiation having enough photon energy.
  6. Apr 24, 2015 #5


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    The H2+ molecular ion is stable.
  7. Apr 24, 2015 #6
    You mean ionization by the field alone is almost impossible? But, direct contact with a charged surface of sufficient voltage and geometry will do?
  8. Apr 24, 2015 #7


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    There is this strong field ionization that does rely on the field more than the photon energy to realize the ionization. Typically this is done by focusing an ultrashort high intensity laser pulse onto the gas target.
    That's where the problem lies. Check out "barrier suppression ionization", and use the formula for the so-called critical field (in V/m) to estimate the needed E field strength. Upon getting the value you will realize that using DC field (such as parallel plates or cathode-anode arrangement) and assuming no collisions with free electrons are possible, , the required voltage is just too unreachable.
  9. Apr 24, 2015 #8
    I found a couple papers on 'Barrier suppression ionization", most talk about short pulse lasers like you mentioned. I will read them more thoroughly through the evening.

    I did want to ask if your patience hasn't run out yet. The consensus is h2+ ions require very very high voltages to ionize further. Placing the dome of a van da graaff generator in pure hydrogen, very high voltages would be achieved? Ignoring the difficulty of preventing arcing from the insulation; if the h2+ ions are practically incapable of being stripped of an electron, + charge would continue to build up on the dome?
    Last edited: Apr 24, 2015
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