Which process occurs when a liquid absorbs heat energy without an increase in temperature?

• A. Increase in kinetic energy of liquid molecules
• B. Decrease in potential energy of liquid molecules
• C. Phase change from liquid to gas (vaporization)
• D. Formation of a solid from the liquid (freezing)

Answer: (C)

Verified step by step guidance

1. Understand that when a liquid absorbs heat energy without an increase in temperature, the energy is used to change the phase of the substance rather than increasing the kinetic energy of the molecules.
2. Recall that temperature is related to the average kinetic energy of molecules; if temperature does not increase, kinetic energy remains constant during the process.
3. Recognize that during a phase change, such as vaporization (liquid to gas), the heat energy is used to overcome intermolecular forces, increasing the potential energy of the molecules.
4. Note that freezing (liquid to solid) releases heat rather than absorbs it, so it does not fit the description of absorbing heat without temperature change.
5. Conclude that the process described is vaporization, where the liquid absorbs heat to change into gas without a temperature increase.