What are the success of quantum free electron theory?

What are the success of quantum free electron theory?

Merits of quantum free electron theory 1. It successfully explains the electrical and thermal conductivity of metals. 2. It can explain the Thermionic phenomenon.

What is one of the success of classical free electron theory?

When an electric field is applied to the metal, the free electrons are accelerated in the direction opposite to the direction of applied electric field. Success of classical free electron theory: It explains the electrical and thermal conductivities of metals.

What are the success and failures of classical free electron theory?

1) It fails to explain the electric specific heat and the specific heat capacity of metals. 2) It fails to explain superconducting properties of metals. 3) It fails to explain new phenomena like photo-electric effect, Compton effect, Black body radiation, etc.

What is the need of quantum free electron theory?

Quantum free electron theory was proposed by Arnold Sommerfeld. As per his investigation, the behavior of free electron in different possible energy states is explained, how the large number of electrons are disturbed in the energy states.

What are the failures of quantum free electron theory?

Drawbacks of Quantum free electron theory 1. This theory fails to distinguish between metal, semiconductor and Insulator. 2.It also fails to explain the positive value of Hall Co-efficient. 3.

How is quantum free electron theory different from classical free electron theory?

According to classical theory, the free electrons in a metal have random motions with equal probability in all directions. But according to quantum theory, the free electrons occupy different energy levels, up to Fermi level at 0 K. So, they possess different energies and hence they possess different velocities.

What is the difference between classical free electron theory and quantum free electron theory?

Who Will proposed free electron theory?

The free-electron model was first proposed by the Dutch physicist Hendrik A. Lorentz shortly after 1900 and was refined in 1928 by Arnold Sommerfeld of Germany. Sommerfeld introduced quantum-mechanical concepts, most notably the Pauli exclusion principle.

What are the merits and demerits of quantum free electron theory?

Advantages of Quantum free electron theory 1. This theory fails to distinguish between metal, semiconductor and Insulator 2. It also fails to explain the positive value of Hall Co-efficient. 3.

What are the shortcomings of free electron theory?

1) It fails to explain the electrical conductivity of semiconductors and insulators. temperature. 3) It fails to explain the concept of specific heat of metals. 4) It fails to explain the mean free path of the electrons.

What are the postulates of quantum theory?

The total wavefunction must be antisymmetric with respect to the interchange of all coordinates of one fermion with those of another. Electronic spin must be included in this set of coordinates. The Pauli exclusion principle is a direct result of this antisymmetry principle.

What are the drawbacks in classical free electron theory explain the how quantum free electron theory assumptions overcome the drawbacks?

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.

What is the success of quantum free electron theory of metals?

Success of quantum free electron theory of metals: 1. Specific heat of solid: At zero kelvin energy levels under Fermi energy level are filled by electrons. When the temperature is increased to room temperature few number lo electrons conduct heat or electricity.

What is the difference between classical and quantum free electrons?

The classical free electron theory Drude and Lorentz proposed this theory in 1900. According to this theory, the metals containing the free electrons obey the laws of classical mechanics. The quantum free electron theory Somerfield developed this theory in 1928. According to this theory the free electrons obey quantum laws.

What is the free electron theory?

According to this theory, the metals containing free electrons obey the laws of classical mechanics. (ii). The Quantum free electron theory: Sommerfeld developed this theory during 1928. According to this theory, the free electrons obey quantum laws.

What are the two theories of electron motion?

electrons obey quantum laws. According to this theory the free electrons are moving in a constant potential. The zone theory Bloch stated this theory in 1928. According to this theory, the free electrons move in a periodic field provided by the lattice. According to this theory the free electrons are moving in a constant potential. 2.