Famous Is Natural Gas Lighter Than Air 2023. Oxygen is denser than both air and nitrogen, at all temperatures and pressures, but only slightly. There's also a quick primer on gas densities here.
1.204 kg/m³ (0.07516 lb/ft³) of air. These gases must have a molecular mass less than 28.97 (the average molecular mass of air) and exist as a gas at atmospheric temperatures and atmospheric pressures. Natural gas should rise to high places, assuming that it isn't much colder than its surrounding air.
