diffusion coefficient

This term is a technical specification used primarily in physics, chemistry, and materials science. It describes the ease with which particles move through a specific medium, where a higher value indicates faster movement. It is almost exclusively used in formal, academic, or industrial contexts and is rarely encountered in general conversation.

Because it is a specific physical constant, it is treated as a countable noun when referring to different coefficients for different substances or conditions (e.g., comparing the diffusion coefficients of two different gases).