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

The energy of the incident radiation, $E=h\nu =\frac{hc}{\lambda }=\frac{6.626\times {10}^{-34}\times 3.0\times {10}^8}{256.7\times {10}^{-9}}=7.74\times {10}^{-19}J$.
Convert the unit in eV.
$E=\frac{7.74\times {10}^{-19}}{1.602\times {10}^{-19}}=4.83eV$
The potential energy is equal to 0.35 eV.
The work function is $4.83eV-0.35eV=4.48eV$.