The ejection of the photoelectron from the silver metal in the photoelectric effect exeriment can be stopped by applying the voltage of `0.35 V` when the radiation `256.7 nm` is used. Calculate the work function for silver metal.

Explanation

Energy of incident radiation
= Work function + K.E. of photoelectron Energy of incident radiation,
`E = hv = (hc)/(lambda)`
`= ((6.626 xx 10^(-34) Js) xx (3.0 xx 10^8 ms^(-1)))/((256.7 xx 10^(-9)m))`
`= 7.74 xx 10^(-19) J`
or `= (7.74 xx 10^(-19)J)/(1.602 xx 10^(-19)) = 4.83 eV`
The potential energy given the kinetic energy to the electrons.
Hence `K.E.` of the electron = 0.35 eV
Work function = `4.38 eV = 0.35 eV = 4.48 eV`.