An explanation of the photoelectric effect includes the terms photon energy and work function energy.
Explain what is meant by
a photon,
work function energy.
In an experiment to investigate the photoelectric effect, a student measures the wavelength 
of the light incident on a metal surface and the maximum kinetic energy 
of the emitted electrons. The variation with of 
is shown in the graph below.
The work function energy of the metal surface is 
. State an equation, in terms of , and , to represent conservation of energy for the photoelectric effect. Explain any other symbols you use.
Use your answer in (i) and the graph above to determine
the work function energy of the metal surface,
a value for the Planck constant.
that is directly proportional to its frequency 
, the energy is given by the equation:
is Planck’s constant.
is the speed of light and 
.
.
