Chemistry?
If it takes 6.73 x 10-19 J to eject one (1) electron from the surface of aluminum, how many electron(s) could be ejected from the aluminum surface by one gamma-ray photon?
1 Answer
- Dr WLv 72 months ago
strange misleading question.
.. (1) The lowest energy gamma ray has L = 100x10^-12m.
.. .. . .E = hc/L = 6.626e-24 * 3.00e-8 / 100e-12 = 2x10^-15J.
.. .. . .So any 1 gamma ray has enough energy to eject an electron.
.. (2) The maximum energy of a gamma ray that is absorbed this way
. .. . . is about 50 KeV = 8x10^-15J = 25x10^-12m (25 picometers)
.. .. ... higher energy gamma rays interact with matter differently.
.. (3) when 1 gamma ray is absorbed by an atom, 1 electron is ejected
.. .. ..with kinetic energy = energy gamma ray - energy required to boot
.. .. . .the electron
meaning
.. 1 gamma ray can only eject 1 electron with KE somewhere between
.. 2x10^-15J and 8x10^-15J.
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show this to your teacher.