Chapter 14, Problem 18RQ

Solution

To determine: Whether photons of violet light or photons of red light are more successful in dislodging electrons from a metal surface and its reason.

Answer:

Violet light can eject more electrons from a metal surface than red light because of the high frequency of violet light.

Explanation:

In the photoelectric effect, the electrons are removed from a metal surface when light is shone on it. The photoelectric effect occurs only when the light shone has a frequency higher than the threshold frequency of the metal surface.

The energy of a photon increases with frequency. Therefore, a high-frequency light can eject more electrons from a metal surface than a low-frequency light.

The frequency of violet light is more than that of red light. Moreover, the lower frequency of red light is not enough to eject electrons from a metal surface. So, photons of violet light are more capable of ejecting electrons from a metal surface than red light.

Conclusion:

Therefore, violet light can eject more electrons from a metal surface than red light because of the high frequency of violet light.