Question

According to the band theory, increase in number of atoms participating in crystal formation leads to ________ in number of molecular orbitals containing electrons.

• A. decrease
• B. no change
• C. increase
• D. either increase or decrease, depending upon the size of the atoms

Answer 1

The correct option is C increase

Overlap of atomic orbitals in solids ​gives rise to bands ​
of energy levels.​ The band theory assumes that atomic orbitals of the atoms of the crystal combine to form molecular orbitals which are spread over the whole crystal structure. Hence, the number of atoms is directly proportional to the number of molecular orbitals formed.