What happens to molecules in a warm air column?

In a warm air column, molecules gain kinetic energy as the temperature increases. This increase in kinetic energy causes the molecules to move faster and, as a result, to spread apart from one another. The increased motion leads to a decrease in density, which is a characteristic feature of warm air. Warm air is less dense than cooler air, allowing it to rise. This dynamic is fundamental in meteorological processes, such as the formation of clouds and convection currents.

While the other options touch on various physical states or behaviors of molecules, they do not accurately describe the processes that occur in a warm air column. For example, the notion that molecules move slower and become denser describes cooler air rather than warm air. The transition to a liquid state applies to specific conditions such as condensation, which is not a direct result of the warmth of an air column. Lastly, the idea that molecules remain stationary contradicts the fundamental principles of thermodynamics, as all molecular motion increases with temperature.