Question

The work function for a metal surface is 3.82 eV. What is the largest wavelength of light in nm that will produce photoelectrons from this surface?1 eV = 1.602 ? 10?19 J,
e = 1.602 ? 10?19 C,
c = 2.998 ? 108 m/s,
and
h = 6.626 ? 10?34 J

Answer 1

Answer:

The largest wavelength of light that will produce photoelectrons from this surface is 324.6 nm.

Explanation:

Given;

work function, Ф = 3.82 eV

The work function of the metal is minimum energy required to produce electron from the metal surface.

Ф = hf

where;

h is Planck's constant = 6.626 x 10⁻³⁴ J/s

f is the frequency of the photon

f = c / λ

$\phi = \frac{hc}{\lambda}$

where;

c is speed of light = 2.998 x 10⁸ m/s

λ is the wavelength = ?

$\phi = \frac{hc}{\lambda}\\\\\lambda = \frac{hc}{\phi }\\\\\lambda = \frac{(6.626*10^{-34})(2.998*10^8)}{3.82*1.602*10^{-19}}\\\\\lambda = 3.246*10^{-7} \ m\\\\\lambda = 324.6 *10^{-9} \ m\\\\\lambda = 324.6 \ nm$

Therefore, the largest wavelength of light that will produce photoelectrons from this surface is 324.6 nm.