(a)[3]
Electromagnetic radiation with one constant frequency is incident on a metal surface. An electron is emitted. Explain why the maximum kinetic energy of the electron does not depend on the intensity of the incident radiation.
(b(i))[3]
Ultraviolet radiation with wavelength $250\,\text{nm}$ falls on the surface of a zinc sheet. The maximum kinetic energy of the emitted electrons is $1.4\,\text{eV}$. Determine, in $\text{eV}$, the energy of a photon in the ultraviolet radiation.
(b(ii))[2]
Ultraviolet radiation with wavelength $250\,\text{nm}$ falls on the surface of a zinc sheet. The maximum kinetic energy of the emitted electrons is $1.4\,\text{eV}$. Determine, in $\text{eV}$, the work function energy of the surface of the zinc.