Photoelectric Effect Notes

The Intensity of the light/radiation affects the number of protoelectrons emmitted. More intense - More photoelectrons.

The Frequency of the light/radiation affects the kinetic energy of the ejectrons.

Threshold frequency is the minimum frequency required to eject electrons from different metals. F0

E=HF0 = Θ = work function.
The work function is the minimum amount of energy required to eject electronsfrom the nucleus.

The energy of the ejectrons depends on the KE they had before the ejection.























For the threshold requency :



above the threshold frequency :








UNIT - Electron volt: eV

1 electron volt (eV) = the energy required to move 1 electron through a PD of 1V

1eV = e * 1V

= 1.6*10^-19 J


(theta) caesium = 3.11*10^-19 J = 1.94 eV
(theta) copper = 7.44*10^-19 J = 4.65 eV