Question

The ejection of the photoelectron from the silver metal in the photoelectric effect experiment 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.

Answer 1

Of the principle of conservation of energy, which states that the energy of an incident photon (E) is equivalent to the sum of the work function (W0) of radiation and it's kinetic energy (K.E), i.e.,

 

Energy of incident radiation(E)= hc/λ = (6.626x10-34)(3x108)/(256.7x 10-9)

= 7.74x10-19 J and  

 

the potential gives the kinetic energy to the radiation, therefore K.E of the electron =. 0.35Ev

 

So, work function = 4.83 – 0.35 = 4.48 eV