Which of the following processes is not a surface phenomenon?
Answer Details
Out of the given options, both Condensation and Evaporation are surface phenomena, while Photo Emission and Thermionic Emission are not.
Condensation is the process of converting a gas or vapor into a liquid by cooling it down. This process occurs on the surface of a solid or liquid and is a surface phenomenon.
Evaporation is the process of converting a liquid into a gas or vapor by heating or increasing its surface area. This process also occurs on the surface of a solid or liquid and is also a surface phenomenon.
Photo Emission and Thermionic Emission, on the other hand, are not surface phenomena.
Photo Emission is the process of electrons being emitted from a material when it absorbs light of a certain frequency. This process occurs in the bulk of the material and not just on the surface.
Thermionic Emission is the process of electrons being emitted from a heated material due to its high temperature. This process also occurs in the bulk of the material and not just on the surface.
In summary, Condensation and Evaporation are surface phenomena, while Photo Emission and Thermionic Emission are not.