What distinguishes a mixture from an impure substance?

Mixture can be separated into its components but impure substance cannot be separated into components.

Explanation:

A mixture is defined as a combination of two or more different substances in which the component substances are individually distinct. The substances can be separated by physical processes. The separation dos not involve any chemical process because no new substance is being formed.

Impure substance is defined as a substance which can be mixture of elements, compounds or elements and compounds. The substances cannot be separated by physical means but can only be separated by chemical means.

dynamic equilibrium is the answer.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa