What happens to NH3 at its boiling point?

When ammonia (NH3) reaches its boiling point, it undergoes a phase change from liquid to gas, which is referred to as vaporization. At the boiling point, the temperature at which the liquid phase can transition to the gaseous phase becomes attainable, allowing the molecules of ammonia to gain enough energy to overcome intermolecular forces. As a result, they escape into the air as a gas. This process is crucial in various applications, such as refrigeration and chemical manufacturing, where the properties of ammonia in its gaseous state play an essential role.

The other options describe different physical changes. Solidification refers to a substance transitioning from a liquid to a solid at temperatures below its freezing point, while freezing specifically concerns liquids forming solids at low temperatures. Condensation, on the other hand, occurs when a vapor turns back into a liquid as it loses energy, which is the opposite process of what happens at the boiling point.