Question

Energy bands in solids are a consequence of,

• A. Ohm's law
• B. Bohr's theory
• C. Heisenberg's uncertainty principle
• D. Pauli's exclusion principle

Answer 1

The correct option is D Pauli's exclusion principle

According to Pauli's exclusion principle, two electrons cannot have the same quantum numbers, in a given atom. Therefore, when two identical atoms combine to form a diatomic molecule, each atomic orbital (i.e. energy level) splits up into two different molecular orbitals (having different energies).
This allows the electrons in the first atomic orbitals to occupy a new orbital structure, but none of the molecular orbitals have the same energy.

Hence, $\left(B\right)$ is the correct answer.