Experiments are conducted to investigate the photoelectric effect.
It is found that, on exposure of a metal surface to light, either electrons are emitted immediately or they are not emitted at all. Suggest why this observation does not support a wave theory of light.
Data for the wavelength 
of the radiation incident on the metal surface and the maximum kinetic energy 
of the emitted electrons are shown in the table below.
Without any calculation, suggest why no value is given for for radiation of wavelength 
.
Use data from the table to determine the work function energy of the surface.
Radiation of wavelength 
gives rise to a maximum photoelectric current 
. The intensity of the incident radiation is maintained constant, and the wavelength is now reduced. State and explain the effect of this change on
the maximum kinetic energy of the photoelectrons,
the maximum photoelectric current .
.
