Arrow I corresponds to:

• A. Equilibrium
• B. Sublimation
• C. Condensation
• D. Vaporization
• E. Deposition

Answer: (C)

Verified step by step guidance

1. Examine the phase diagram provided in the image. The diagram shows the phases of a substance as a function of pressure (P) and temperature (T).
2. Identify the regions in the phase diagram: the solid region is to the left, the liquid region is at the top, and the gas region is at the bottom.
3. Locate Arrow I on the diagram. It points upwards from the gas region to the liquid region, indicating a change in phase.
4. Understand the phase change represented by Arrow I. Since it moves from the gas phase to the liquid phase, this process is known as condensation.
5. Condensation is the process where a gas turns into a liquid, typically by cooling or increasing pressure, which is consistent with the direction of Arrow I in the phase diagram.