1.67 points when comparing equal volumes of gases at the same pressure and temperature, different gases have different densities. which property or properties of gas particles contribute to different gases having different macroscopic densities

Molar mass due to different atomic masses

Explanation:

Two gases that have the same volume, pressure and gases have the same number of moles, as we can deduce from the ideal gas equation. So the gases will have the same number of moles of gases but they can have densities due to the fact that they have different molar masses due to the fact that they have different atomic masses. So one gas will be heavier than the other, for the same volume.