What summarizes the differences between sublimation and melting?

The correct answer highlights a fundamental distinction between sublimation and melting based on their phase changes. Sublimation is the process where a solid transitions directly into a gas without first becoming a liquid. This occurs at specific conditions of temperature and pressure, allowing certain solids (like dry ice) to bypass the liquid phase entirely.

In contrast, melting specifically refers to the transformation of a solid into a liquid upon reaching its melting point. This transition occurs when heat is applied, enabling solid molecules to gain sufficient energy to overcome the forces holding them in a rigid structure, thus becoming a liquid.

This understanding is crucial in the context of physical chemistry and material science, as it illustrates the different behaviors of substances under various conditions.