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Thermionic emission

  1. Nov 27, 2015 #1
    If there is continue emission of electrons from surface then what will
    be its effect on that surface? Some of my friends told me that there are
    billions billions electrons. Nothing happen. But i think there is also emission of billions of electrons within small time. Can this process make a deficiency of electrons on the surface ? Can it completely remove all the electrons?
  2. jcsd
  3. Nov 27, 2015 #2
    No. As you remove more electrons, you are leaving behind more positive charge, which will prevent further electron removal. You will need more and more energy to remove more electrons.
  4. Nov 27, 2015 #3
    the object will have less electrons hence becomes positively charged. the increased potensial will cause higher limit of foton energy to free more electron until it stops the electron emission.
    you can find a video in youtube where a gold leaf electrode is exposed to ultraviolet radiation then the leaf spreads out. when the radiation is visible light the leaf doesnt move.
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