In frost, water is found in which state?

Correct answer: Solid state

Correct answer: C, the solid state. Frost is a deposit of ice crystals that forms on a cold surface when the temperature is sufficiently low. Water vapour changes into solid ice crystals, often without first becoming visible liquid water; this change is called deposition. Even if the surrounding air contains invisible vapour, the water that we see as frost is solid. A is incorrect because liquid droplets on a cool surface are characteristic of dew, not frost. B is incorrect because vapour is the gaseous form and cannot itself be seen as the white crystalline coating called frost. D is incorrect because plasma is a highly energetic state of matter and has no role in ordinary frost formation. A useful comparison is: dew is liquid water on a cool surface, whereas frost is solid ice on a sufficiently cold surface. Memory cue: “dew drops, frost crystals.”