A surface has a work function 1.70 eV and has light of wavelength 400 nm shone on it. What is the kinetic energy of the photoelectrons emitted?
A)4.52 eV
B)3.11 eV
C)1.41 eV
D)2.82 eV
E)1.70 eV

Question

Quizplus · Accepted Answer

The energy of the incident photons is calculated using the formula E = hc/λ, where h is Planck's constant (4.135667696 x 10^-15 eV·s), c is the speed of light (3 x 10^8 m/s), and λ is the wavelength (400 nm = 400 x 10^-9 m). This gives E ≈ 3.11 eV. The kinetic energy of the emitted photoelectrons is the photon energy minus the work function: KE = 3.11 eV - 1.70 eV = 1.41 eV.

A Surface Has a Work Function 1