What are the drawbacks of classical free electron theory
Answers
Explanation:
Classical theory states that all free electrons absorb the supplied energy. But quantum theory states that only a few electron absorb the supplied energy.
2. The electrical conductivity of semiconductor and insulator cannot be explained by this theory.
3. The concept of photo - electric effect, Compton effect and black body radiation cannot be explained on the basis of this theory because these phenomenon are based on quantum theory.
4. The susceptibilities of a paramagnetic material is inversely proportional to the temperature. But, experimental result shows that para-magnetism of a metal is independent of temperature. Moreover, the ferro-magnetism cannot be explained by this theory.
•The drawbacks of classical free
electron theory :
1)The classical free electron model
predicts the incorrect temperature
dependence of σ.
2) It fails to give a correct
mathematical expression for
thermal conductivity.
3) Ferromagnetism could not be
explained by this theory.
4) Susceptibility has greater
theoretical value than the
experimental value.
5) It fails to explain the electric
specific heat and the
specific heat capacity of metals.
6) It fails to explain
superconducting properties of
metals.
7) It fails to explain new phenomena
like photo electric effect,
Compton effect, Black body
radiation, etc.
8) It fails to explain electrical
conductivity of semiconductors
or insulators.