In adiabatic cooling, how does air cool without external heat loss?

Correct answer: It uses internal energy while expanding

Answer: A. Adiabatic cooling occurs when a moving air parcel expands without exchanging significant heat with its surroundings. Rising air enters regions of lower atmospheric pressure. The lower outside pressure allows the parcel to expand. Expansion requires work, and because no external heat is supplied, the parcel uses some of its internal energy to do that work. Its temperature therefore falls. A is correct because it describes the internal-energy change during expansion. B is wrong because water vapour does not become soil. C is wrong because adiabatic cooling is specifically discussed without direct heat exchange; sunlight is not the mechanism in this process. D is wrong because rising air generally moves into lower pressure rather than permanently increasing pressure. If the air cools to its dew point, condensation may begin. Memory cue: rising air expands and cools; sinking air compresses and warms.