The passage or diffusion of a gas, vapor, liquid, or solid through a barrier is referred to as its _____?

Permeability is defined as the ability of a material to allow substances such as gases, vapors, liquids, or solids to pass through it. This property is crucial in various fields such as engineering, geology, and environmental science. In the context of materials, permeability indicates how easily these substances can diffuse across a barrier, which makes it a fitting term for the passage of different phases through an interface or membrane.

While porosity relates to the volume of voids in a material that can hold fluids, it does not directly measure the ease of passage through that material. The diffusion rate pertains to how quickly a substance moves across a given area, but it is not the characteristic that describes the overall ability of a material to facilitate that movement. Absorption, on the other hand, refers specifically to the uptake of one substance by another, which is not the same as permeability. Thus, permeability is the most appropriate choice for describing the passage through barriers.