Question

melting can be best described as a process in which molecules

• lose kinetic energy and remain stationary
• lose kinetic energy and move slowly
• gain kinetic energy and escape into the atmosphere
• gain enough kinetic energy to get past each other

Explanation:

Analyze the phase change process

Using the Phase Changes knowledge point

Melting is the transition from a solid to a liquid. In a solid, molecules are held in fixed positions by strong intermolecular forces and can only vibrate. As heat is added, the molecules gain kinetic energy.

Evaluate the molecular behavior

Using the Phase Changes knowledge point

To melt, molecules must gain enough kinetic energy to overcome the fixed intermolecular attractions holding them in place, allowing them to slide and get past each other into a fluid liquid state.

Match with the correct option

Using the Phase Changes knowledge point

• "lose kinetic energy..." is incorrect because melting requires heating (gaining energy).
• "gain kinetic energy and escape into the atmosphere" describes vaporization/boiling, not melting.
• "gain enough kinetic energy to get past each other" correctly describes melting.

Answer:

• lose kinetic energy and remain stationary
• lose kinetic energy and move slowly
• gain kinetic energy and escape into the atmosphere
• gain enough kinetic energy to get past each other (Correct answer)