Question

Light of wavelength 400 nm falls on a metal surface having a work function 1.70 eV. What is the maximum kinetic energy of the photoelectrons emitted from the metal?

a. 4.52 eV
b. 3.11 ev
c. 141 eV
d. 2.82 eV
e. 1.70 eV

Answer 1

Ke = 1.41 eV

Step-by-step explanation:

We know that

h = 6.626 x 10⁻²⁴

c = 3 x 10⁸

λ = 4 x 10⁻⁹ x 1.6 x 10⁻¹⁹

Computation:

Ke = [hc / λ] - w

Ke = [(6.626 x 10⁻²⁴)(3 x 10⁸) / (4 x 10⁻⁹ x 1.6 x 10⁻¹⁹)] - 1.70

Ke = 1.41 eV