When a metal was exposed to light at a frequency of 4.23× 1015 s–1, electrons were emitted with a kinetic energy of 4.80× 10–19 J. What is the maximum number of electrons that could be ejected from this metal by a burst of light (at some other frequency) with a total energy of 3.27× 10–7 J?

Question

jfraser · Answer

knowing the frequency of incoming light tells you the energy of the incoming light by using $$E = h*\nu$$. knowing the kinetic energy of the ejected electrons allows us to find the binding energy of the electrons, the energy needed to break them free from the atom:$$E_{incoming} = BE + KE_{outgoing}$$so$$BE = E_{incoming} - KE_{outgoing}$$Some other amount of light with a different energy will be able to release a different number of electrons, theoretically$$no.e^{-1} released = \frac{E_{total}}{BE_{electron}}$$