State what is meant by a photon.
It has been observed that, where photoelectric emission of electrons takes place, there is negligible time delay between illumination of the surface and emission of an electron. State three other pieces of evidence provided by the photoelectric effect for the particulate nature of electromagnetic radiation.
The work function of a metal surface is 
. Light of wavelength 
is incident on the surface. Determine whether electrons will be emitted, by the photoelectric effect, from the surface.
that is directly proportional to its frequency 
, the energy is given by the equation:
is Planck’s constant.
, which is less than the work function of the metal surface, so electrons will not be emitted, by the photoelectric effect, from the surface.
