Work Function

Description:

An atom consist of a positively charged nucleus and negatively charged electrons that revolve around the nucleus in various orbits. Each electron possess some amount of potential energy with which it is bounded to the atom.

If an electron receive extra energy from an external source, the electron will come out of its orbit as a free electron. It is also known as lose bound electron.

In a metal number of atoms are present and some loosely bound electrons are also present.

A free electron within a metal cannot jump outside the metal because initially the net charge on metal is zero, if an electron jumps out of the metal, the metal will acquire a positive charge due to loss of electron and as electron is negatively charge and is light in weight it will be pulled back into the metal due to the force of attraction.

If the free electron in the metal is to be removed from the metal, energy equal to the potential barer (potential difference created when electron leaves the metal surface) should be provided to the electron and this energy is known as work function.

Work function is the minimum energy to be given to electron of a material so that it comes out of the surface without possessing any velocity.

Work function is defined for metal and not for electron as work function required to free the electron is different for different type of metal.

Work function for different metals are as shown below −