AFOQT Practice Test

What occurs during condensation?

1. Gas changes to solid

2. Liquid changes to gas

3. Gas changes to liquid

4. Sublimation of solid

The correct answer is: Gas changes to liquid

Condensation is the process where a substance transitions from a gas phase to a liquid phase. This occurs when the gas cools down and its molecules lose energy, causing them to come closer together and form a liquid. This phenomenon is commonly observed in nature, such as when water vapor in the air cools and forms droplets on a surface, like a glass of cold water. This distinction is important because it highlights the behavior of gases in response to temperature changes and the principles of thermodynamics involved in phase transitions. The other choices illustrate different phase changes: a gas to a solid phase is deposition, a liquid becoming a gas is evaporation, and sublimation refers to a solid transitioning directly to a gas. Each of these processes is distinct, making the identification of condensation specifically as the gas-to-liquid transition key to understanding the overall concepts of phase changes.