1. Frequency of the incident light:
* The most important factor: The kinetic energy of the ejected electron is directly proportional to the frequency of the incident light. This is expressed by the equation:
* KE = hf - Φ
where:
* KE is the kinetic energy of the electron
* h is Planck's constant
* f is the frequency of the incident light
* Φ is the work function of the metal (the minimum energy required to remove an electron from the metal)
* Higher frequency light means higher energy photons: Higher energy photons impart more energy to the electrons, resulting in higher kinetic energy and therefore higher velocity.
2. Work function of the metal:
* The minimum energy required to eject an electron: The work function is a property of the specific metal being illuminated.
* Lower work function means easier ejection: Metals with lower work functions require less energy to eject electrons. This means that even low-frequency light can eject electrons, but with lower kinetic energy and velocity.
Here's a breakdown of the relationship:
* If the frequency of the incident light is below the threshold frequency (f < Φ/h), no electrons will be ejected, regardless of the intensity of the light.
* If the frequency of the incident light is above the threshold frequency (f > Φ/h), electrons will be ejected, and their kinetic energy will increase with the frequency of the light.
* The intensity of the light affects the number of electrons ejected, but not their individual kinetic energies (velocities).
Therefore, the velocity of an electron in the photoelectric effect is directly related to the frequency of the incident light and inversely related to the work function of the metal.
