Is NH3 lighter than air?

Ammonia (NH3) is indeed lighter than air. This characteristic is important in various applications, including industrial settings and hazardous material scenarios, because it affects how ammonia disperses in the atmosphere.

The molecular weight of ammonia is about 17 g/mol, while the average molecular weight of air is approximately 29 g/mol. Because ammonia has a lower molecular weight, it generally rises and disperses more quickly when released into the atmosphere. This property is a critical factor to consider in safety and ventilation planning, as it influences the potential for ammonia to accumulate in enclosed spaces or how it may behave in the event of a leak.

In contrast, other options may reflect misunderstandings or nuances regarding ammonia's behavior under specific conditions, but they do not accurately capture the fundamental property that ammonia is lighter than air in its standard gaseous state.