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Title: How many electrons are emitted from a square centimeter of the surface each second? Post by: illestchemist on Sep 7, 2012 Ultraviolet light is incident normally on the surface of a certain substance. The binding energy of the electrons in this substance is 3.44 eV. The incident light has an intensity of 0.045 W/m2. The electrons are photoelectrically emitted with a maximum speed of 4.7 105 m/s. How many electrons are emitted from a square centimeter of the surface each second? Assume that the absorption of every photon ejects an electron.
Title: How many electrons are emitted from a square centimeter of the surface each second? Post by: tonichilds83 on Sep 7, 2012 You start by finding the energy of the emitted electrons.
ke=1/2mv^2 That energy plus the binding energy is the energy of the photons Find the amount of energy impacting a square centimeter. Only a percentage of that is absorbed however, I don't know how you would find that. Maybe you assume all of it is absorbed. (Write down that you have made that assumption if you do) You divide the absorbed energy by the energy per photon to find the number. |