Photoelectric effect Flashcards
What is the Threshold frequency?
For a given metal, no photoelectrons are emitted if the radiation frequency is below a certain value.
Explain effect of light intensity on emitted electrons
The number of photoelectrons emitted increases with increasing light intensity
Explain effect of frequency of radiation on emitted photoelectrons
Photoelectrons are emitted with a range of kinetic energies. The value of maximum kinetic energy increases with the frequency.
Equation for Threshold frequency
Threshold frequency = work function/planck’s constant
De Broglie Wavelength
Wavelength=Planck’s constant/mass X velocity
Explain why photoelectric effect is not observed below threshold frequency
No photoelectrons are emitted if the frequency of the radiation is below the threshold frequency.
Why do emitted electrons have a range of kinetic energies?
The kinetic energy an electron will be carrying when it leaves the metal is E=hf minus any other energy losses.
Equation of Kinetic Energy of photoelectron
hf=work function + 1/2mv^2
What is the Work Function?
Minimum energy required to break bonds holding electron to surface of the metal.
