Answer:
See explanation
Step-by-step explanation:
The work function of a metal is defined as that minimum energy which is required to remove one electron from the surface of a metal when it is irradiated with a photon of light. The work function is different for different metals.
The ionization energy of a metal is the energy required to remove an electron from an atom. It depends on the position of the electron within the atom.
The work function specifically refers to the energy required to remove an electron from the conduction band of a metal. Hence, the work function is always lower than the ionization energy.