Question

2 what is the effect of doubling the photon flux of light on whether electrons will be emitted from a metal?
o light with greater photon flux is more likely to cause electrons to be emitted than the weaker light.
o light with greater photon flux will cause electrons to be emitted with faster velocities than the weaker light.
o light with less photon flux must shine for a longer time to cause electrons to be emitted.
o the photon flux has no affect on whether electrons are emitted or not
3 green light shines on an unknown piece of metal, and the lab instruments detect emitted electrons. which of the following will be true if the light is changed to violet?
o violet light will cause electrons to be emitted at greater velocities than those removed by green light.
o violet light will cause electrons to be emitted at lower velocities than those removed by green light.
o violet light will cause electrons to be emitted only if the light has the same photon flux as the green light.
o it cannot be determined whether violet will cause electrons to be emitted or not

Explanation:

Question 2

The photoelectric effect depends on the frequency of light, not photon flux. Photon flux is related to the intensity of light (number of photons). Whether electrons are emitted is determined by if the photon energy (related to frequency) is above the work - function of the metal. Doubling the photon flux just means more photons are hitting the metal, but it doesn't change the energy of each photon. So, it has no effect on whether electrons are emitted.

Violet light has a higher frequency than green light. According to the photoelectric effect equation $K_{max}=h
u - \phi$, where $K_{max}$ is the maximum kinetic energy of the emitted electrons, $h$ is Planck's constant, $
u$ is the frequency of the incident light, and $\phi$ is the work - function of the metal. Since violet light has a higher frequency ($
u$) than green light, the maximum kinetic energy of the emitted electrons will be greater, which means electrons will be emitted at greater velocities.

Answer:

The photon flux has no affect on whether electrons are emitted or not

Question 3