51. A bathroom mirror fogs up during a hot shower. What is the associated phase change?
Answer: B
Condensation occurs when a bathroom mirror fogs up during a hot shower.
When steam from the hot shower comes into contact with the cooler surface of the mirror, the water vapor loses energy and changes back into liquid water, resulting in fog on the mirror.
A) Freezing
Freezing is the process where a liquid turns into a solid, which is not relevant in this context. The situation described involves water vapor turning into liquid water on the mirror's surface, not the transformation from liquid to solid.
B) Condensation
Condensation is the correct answer as it describes the process where water vapor in the air cools down upon contact with a colder surface, such as the bathroom mirror, and changes into liquid water. This is precisely what happens when the mirror fogs up during a hot shower.
C) Evaporation
Evaporation is the process where liquid water turns into water vapor, which is the opposite of what is occurring on the bathroom mirror. In this scenario, water vapor is not being created; instead, it is condensing into droplets on the mirror.
D) Melting
Melting refers to the transition of a solid into a liquid. This phase change is not applicable in this situation, as the process involves water vapor condensing into liquid rather than any solid turning into liquid.
Conclusion
The correct answer, condensation, accurately captures the phase change occurring when the bathroom mirror fogs up due to the cooling of water vapor. All other options fail to represent the situation, as they describe different phase changes that do not apply to the described phenomenon of fogging on a mirror.