Question

Electrons of wavelength 1.5 nm are emitted from a material when light of wavelength 350nm is incident on it. What is the work function of this material?

Answer 1

Answer:

3.5434 eV

Explanation:

For a particle with kinetic energy E and mass m , the wavelength  associated is given by the following relation,

$\lambda=\frac{h}{\sqrt{2mE} }$

E = $\frac{h^2}{2m\lambda^2}$

Putting the values  we get

E = $\frac{(6.6\times(10^{-34})^2}{2\times9.1\times10^{-31\times(1.5\times10^{-9})^2}}$

=1.063 x 10⁻²¹ J

= .0066 eV.

Energy of¹light in terms of eV

= 1244 / 350 = 3.55 eV.

Work function = 3.55 - 0.0066 = 3.5434 eV.