Question

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate the threshold frequency (ν0) and work function (W0) of the metal.

Answer 1

Threshold wavelength of radian = 6800 × 1010m
Threshold frequency (V0)of the metal = $\frac{c}{\lambda_0}$ = $\frac{3\times 10^8\,ms^{-1}}{6.8\times 10^{-7}}$m = 4.41 × 1014 s
Thus, the threshold frequency of the metal is 4.41 × 1014 s.
Hence, the work function (W0) of the metal = (6.626 × 1034 Js) (4.41 × 1014) = 2.922 × 1019 J.