True or False: Pure natural gas is lighter than air.

Pure natural gas is indeed lighter than air. This characteristic is primarily due to its composition, which consists mainly of methane (approximately 70-90%). The molecular weight of methane is about 16 g/mol, which is significantly lower than the average molecular weight of air, approximately 29 g/mol. When natural gas is released into the atmosphere, it tends to rise and disperse, making it less likely to accumulate near the ground where it could pose a hazard such as an explosion or asphyxiation.

Understanding the physical properties of natural gas is vital for fire investigation and safety protocols. For example, if there's a natural gas leak, responders need to recognize that the gas will rise, which influences both evacuation strategies and the placement of ventilation equipment. This knowledge plays a critical role in fire prevention and the safe management of potential gas-related incidents.