If a substance is changing from a vapor to a liquid, like steam on a mirror, it is said to be

volatile

condensing

crystallized

changing pigmentation

condensing

Explanation:

Condensing is the word used to indicate the change of state of a substance from vapor to liquid, as in this case. During condensation, the substance releases thermal energy to the environment, therefore the kinetic energy of the molecules in the vapor decreases until they become closer to each other and they start to be affected by the intermolecular forces and so the substance becomes a liquid.

Explanation:

Condensing is the word used to indicate the change of state of a substance from vapor to liquid, as in this case. During condensation, the substance releases thermal energy to the environment, therefore the kinetic energy of the molecules in the vapor decreases until they become closer to each other and they start to be affected by the intermolecular forces and so the substance becomes a liquid.