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The Nature of Dynamic Equilibrium

publish date: 2026/05/19 08:39:33.935195 UTC

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Once the process of diffusion has fully completed and a fluid mixture achieves a perfectly uniform concentration throughout the container, what happens to the motion of the individual molecules?

The molecules continue to move randomly at high speeds, but their movements yield no further change in net concentration.

All molecular motion drops immediately to zero as the particles lock into balanced static positions.

The molecules reverse their trajectories and migrate back to their original separate starting points.

The particles instantly undergo a phase change and condense into a single dense liquid droplet.

Correct Answer

The molecules continue to move randomly at high speeds, but their movements yield no further change in net concentration.

Explanation

This state is known as dynamic equilibrium. Molecular motion never stops as long as thermal energy is present; however, because the concentration is uniform, the probability of particles moving across any imaginary boundary balances out perfectly in all directions, causing zero net mass transport.

Reference

Basic Physics: A Self-Teaching Guide

Quizzes you can take where this question appears

Diffusion through liquids and gases