Question

What is meant by the work function of a metal? How does the value of work function influence the kinetic energy of electrons liberated during photoelectron emission?

Answer 1

Hint: When we shine a light of a given frequency on a metal, some of the energy of the radiation is used to free the electron from the atoms, which is known as the photoelectric effect. The nucleus pulls electrons into the atom, which must be overcome in order to extract the electron from the atom.

Complete answer:
Work function of metal:-
The amount of energy required to remove an electron from an atom is specified as the work function of a certain metal. The energy of the electron spinning around the nucleus is the same as this. We beam a light of a specific frequency on a metal in the photoelectric effect. The atom receives energy from light. The work function of a metal is defined as the minimal amount of energy required to simply remove an electron from an atom.
The law of conservation of energy states:
A photon's energy is equal to the sum of its threshold energy and its kinetic energy.
Energy of a photon = Threshold energy + Kinetic Energy
The element's work function equals the threshold energy.
 As a result, work function= photon energy- metal kinetic energy.
In equation form, we can write it as:
\[\;K{\text{ }} = {\text{ }}h\nu - q,\]
Where, \[K\] is the kinetic energy, \[\nu \] is the frequency, and q is the metal's work function.
The kinetic energy of the released photo electron falls as the work function of the metal increases.

Note:
 If the incident radiation's energy is less than the metal's work function, the photoelectric effect will not occur. The incident energy is used to pull out the electron, and the remaining energy is transformed into the kinetic energy of the expelled electrons.