# 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?

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• Dr W
Lv 7
2 months ago

.. (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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