Light arrives in particles - small packets of energy called photons
Energy = h * f
Energy = h * c/ lander
h = Planck's constant 6.63 * 10^-34
Electronvolt is the energy acquired by an electron when it passes through a p.d of 1v
eV to J = * 1.60 * 10^-19
J to eV = / 1.60 * 10^-19
Work function is the minimum amount of energy required to release an electron from the surface of a metal
Threshold frequency is the minimum photon frequency required to release a photon from the surface of a metal
Photoelectric effect occurs when a photon has sufficient energy to release a photoelectron from the metal surface
The emission occurs instantly
Einstein's equation
Conservation of energy,
energy = work function + Ke max
Energy = h * f
Energy = h * c/ lander
Graphs
Ke max = hf - work function
y = m x + C
therefore y intercept = work function
gradient = Planck's constant
Wave particle duality
High voltage filament fires electrons that diffract between the gaps of graphite atoms forming concentric circles of the same size as the gap between atoms
