Question

In a crystal, the value of Madelung constant does not depend upon which of the following:

• A. Number of elements in crystal
• B. Number of nearest neighbors
• C. Distance between nearest neighbors
• D. Packing fraction

Hint:

Madelung constant depends on crystal geometry, not on the actual nearest-neighbor distance.

Answer 1

The Correct Option is C

Concept:
Madelung constant is a dimensionless constant used in ionic crystals. It depends on the geometrical arrangement of ions in the crystal lattice.

Step 1: Understand Madelung constant.
Madelung constant is related to the electrostatic interaction of ions in an ionic crystal. \[ \text{Madelung constant}=\text{geometrical factor} \]

Step 2: Dependence of Madelung constant.
It depends on the crystal structure and the arrangement of positive and negative ions.

Step 3: Check distance between nearest neighbors.
The actual distance between nearest neighbors affects the magnitude of potential energy, but the Madelung constant itself is dimensionless and does not depend on the actual distance value. \[ \therefore \text{Correct Answer is (C)} \]