Which factors influence phase change?

• A. Mass and Color
• B. Velocity and Acceleration
• C. Pressure, Absolute Temperature, and Volume
• D. Volume and Density

Answer: (C)

Phase changes happen when a substance crosses the boundaries between solid, liquid, and gas on a phase diagram, which are set mainly by temperature and pressure. At a given pressure, changing the temperature can cause melting, freezing, boiling, or condensation. At a fixed temperature, changing the pressure can also push the substance into a different phase. Volume matters because it’s tied to pressure through how compressible the substance is; in gases, a small volume change at the same temperature can produce a large pressure change that moves the substance into another phase, while for liquids and solids the effect is smaller but still connected. So the factors that influence phase change are pressure, absolute temperature, and volume. Mass and color don’t determine phase transitions, and velocity and acceleration relate to motion rather than phase changes.