Ultraviolet light is shone on a piece of metal, and electrons are observed to be ejected from the metal. The UV lamp is now replaced by a lamp of the same intensity, but which produces photons having a shorter wavelength. Which of the below differences is observed?
A) More electrons per unit time are produced.
B) Nothing changes at all.
C) Electrons with a higher maximum energy are observed.
D) Electrons with lower maximum energy are observed.

Question

Quizplus · Accepted Answer

Electrons are ejected from the metal when they absorb photons with enough energy to overcome the metal's work function. A shorter wavelength means higher photon energy. Therefore, the lamp with shorter wavelength photons will provide higher energy photons, which leads to electrons with a higher maximum energy being ejected.

Ultraviolet Light Is Shone on a Piece of Metal, and Electrons