General Principles of Physiology Practice Exam 2026 – Complete Test Prep

The process that describes marbles dispersing evenly on a frictionless table is diffusion. Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration until equilibrium is reached, where there is an even distribution of particles throughout a given space. In this scenario, when marbles are rolled out onto a frictionless table, they move freely and spread out, similar to how molecules of a substance would move in a solution or gas to balance their concentration.

This concept highlights that diffusion does not require an input of energy; it is a passive process driven by the kinetic energy of the particles involved. In the given example, the marbles represent particles that, upon being released, naturally spread across the surface, mimicking how molecules in a gas or a liquid would diffuse throughout a medium.