Which property of a gas determines how it behaves when mixed with air?

Specific gravity is the property that plays a crucial role in determining how a gas behaves when mixed with air. Specific gravity is a measurement that compares the density of a gas to the density of air. When a gas has a specific gravity less than 1, it is lighter than air and tends to rise. Conversely, if a gas has a specific gravity greater than 1, it is heavier than air and will tend to sink.

This characteristic is essential for understanding the dispersal of gases in the atmosphere, potential hazards of gas leaks, and safety measures that need to be implemented in environments where gases are present. Knowing the specific gravity of a gas helps professionals predict how it will move or accumulate in different spaces, which is critical for ensuring safety and compliance with regulations.

Other properties like viscosity influence the flow of gases but do not directly indicate how they will mix with air. Density, while related, does not provide a direct means to compare with air in the same way that specific gravity does. Flammability indicates the ability of a gas to ignite, which is important for safety but does not directly affect its behavior in terms of mixing with air.