Fog formation is an example of which process?

Correct answer: Condensation

Correct answer: B, condensation. Fog forms when water vapour in moist air cools to the dew point and changes into many tiny liquid water droplets. These droplets remain suspended near the ground, producing the visible cloud-like layer called fog. This is condensation because the change is from a gas, water vapour, to a liquid, water droplets. A is incorrect because evaporation is the opposite change: liquid water becomes water vapour, usually after gaining heat. C is incorrect because weathering is the breakdown of rocks at or near Earth’s surface and is not the process that creates fog. D is not the best answer here because deposition usually means a gas changing directly into a solid, as in the formation of ice crystals in frost; fog consists mainly of liquid droplets. Thus, identifying the state change makes B clear. Memory cue: vapour to liquid is condensation; liquid to vapour is evaporation; vapour to ice is deposition.