When a photon of energy 3.8eV falls on a metallic surface of work function 2.8eV, the photon can transfer its energy to an electron in the metal. If the energy of the photon is greater than or equal to the work function of the metal, an electron can be ejected from the surface of the metal.


The kinetic energy of the emitted electron is given by the difference between the energy of the photon and the work function of the metal. In this case:

Kinetic energy = Energy of photon - Work function of metal
Kinetic energy = 3.8eV - 2.8eV
Kinetic energy = 1.0eV

Therefore, the kinetic energy of the emitted electron is 1.0eV.


When a photon of energy 3.8eV falls on a metallic surface of work function 2.8eV, the photon can transfer its energy to an electron in the metal. If the energy of the photon is greater than or equal to the work function of the metal, an electron can be ejected from the surface of the metal. The energy required to remove an electron from the surface of a metal is called the work function. The work function is a characteristic of the metal and depends on the type of metal and the crystallographic orientation of the surface. The kinetic energy of the emitted electron depends on the energy of the photon and the work function of the metal. The greater the energy of the photon, the greater the kinetic energy of the emitted electron. The kinetic energy of the emitted electron can be calculated using the formula: Kinetic energy = Energy of photon - Work function of metal.

0-1 ev