Question

How the energy band is formed in crystals ?

• A. Atoms on the crystals are moved away from each other
• B. Energy levels of their valence electrons are modified as they are very far from each other.
• C. Energy levels of their valence electrons are modified as they are close to each other.
• D. Crystalline solid contains very small number of atoms

Answer 1

The correct option is C Energy levels of their valence electrons are modified as they are close to each other.

Crystalline solid contains large number of atoms and they are brought close and begin to influence each other. Consequently energy levels of their valence electrons are modified and a collection of large number of closely spaced energy levels are formed, thus forming an energy band.