Question

If \( n \) is the number density and \( d \) is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e., mean free path) is represented by:

• A. \( \frac{1}{\sqrt{2\pi n d^2}} \)
• B. \( \sqrt{2n \pi d^2} \)
• C. \( \frac{1}{\sqrt{2} n \pi d^2} \)
• D. \( \frac{1}{\sqrt{2n^2\pi^2 d^2}} \)

Hint:

The mean free path decreases with increasing molecular diameter or number density. For smaller \( d \) and \( n \), molecules travel longer distances before colliding.