Question

Define: photoelectric work function.

Answer 1

Hint: The photoelectric work function is associated with the photoelectric effect. The photoelectric effect is associated with the particle nature of light.

Complete step by step answer
In the photoelectric effect, when photons that have energy above a certain threshold, interact with a metal, they eject electrons from the metal surface which is measured in the form of an electric current.
The photoelectric work function is the threshold energy required by the radiation or photons that are incident on the surface of the metal. We can use the term radiation interchangeably with photons in this case.
Mathematically, the photoelectric work function $ \left( \phi \right) $ can be associated with the threshold of the frequency above which the photoelectric effect will occur for a given metal as
 $ \phi = h{\nu _0} $ where $ h $ is the Planck’s constant and $ {\nu _0} $ is the threshold frequency. The incoming radiation must have energy higher than the threshold work function to cause the photoelectric effect. This can be written as that the frequency of the incoming radiation must be higher than the threshold frequency of the metal to cause the photoelectric effect.
As a cause of the photoelectric effect, an electron will be ejected from the metal surface for each photon that interacts with the metal surface properly. The energy of the ejected electron will be less than the energy of the incoming photon as the electron will have to overcome the work function of the metal which will utilize some of the incoming energy.

Note
The photoelectric work function is a characteristic property of different metals. This implies that every metal has a different work function which depends on the properties of the metal.