Question

A student wants to calculate the refractive index of NaCl crystal with accurate measurements. He gets different values of refractive index for different directions. Reason for this is

• A. Strong intermolecular forces between ions.
• B. Because of the way of arrangement of ions.
• C. Because of different ions present in the crystal.
• D. Because of presence of gaps.

Answer 1

The correct option is B

Because of the way of arrangement of ions.

Let’s think about refractive index. If it is different from different directions then it should be anisotropic.

It will look something like this.

Here we can see that it is different from different directions.
What did you observe?

$\to$ It is because of the arrangement of particles.

Therefore, options (b) is correct.