What happens to a liquid at its boiling point?

At the boiling point, a liquid undergoes a significant transformation where it begins to vaporize steadily and can transition into the gaseous state. This phenomenon occurs when a liquid's temperature reaches the point at which its vapor pressure equals the atmospheric pressure surrounding it. At this stage, bubbles of vapor can form within the liquid and rise to the surface, allowing the liquid to convert into gas.

This process is crucial in many applications, such as cooking and industrial processes, where heating a liquid allows for efficient steam generation or other vapor-related activities. The boiling point is not just a threshold; it represents a dynamic state where the liquid is actively changing into vapor.

In contrast, the other choices do not accurately depict the behavior of a liquid at its boiling point. For instance, stating that a liquid stops vaporizing entirely misrepresents the continuous nature of vaporization at this point, while claiming that it produces no vapor contradicts the very essence of reaching the boiling point. Additionally, suggesting that boiling is unsustainable and leads to quick cooling doesn't reflect the stable nature of liquids transitioning to gas under consistent heating conditions.