What is the primary distinction between boiling and evaporation?

The primary distinction between boiling and evaporation lies in the conditions under which each process occurs. Evaporation is a surface phenomenon that can take place at any temperature below the boiling point of a liquid. This means that even at lower temperatures, molecules at the surface can gain enough energy to overcome intermolecular forces and escape into the gas phase.

In contrast, boiling is a bulk phenomenon that occurs throughout the entire liquid. It happens at a specific temperature known as the boiling point, which is determined by the atmospheric pressure. When a liquid reaches this temperature, bubbles of vapor form within the liquid and rise to the surface, where they escape into the air.

The other options present misunderstandings of these concepts. Boiling is not limited to high altitudes; it occurs at specific boiling points that can vary with pressure. Additionally, boiling occurs throughout the liquid, not just at the surface, while evaporation is primarily associated with surface molecules. Lastly, evaporation does not occur at a specific temperature; it can occur at any temperature below the boiling point, making it distinct from the boiling process.