Final answer:
The combination of dispersed phases and dispersing media that cannot form a colloid is gas and gas (e), as when gases mix, they form a true solution, not a colloid. In contrast, other pairings like solid-gas, liquid-gas, solid-solid, and liquid-liquid can form colloids.
Step-by-step explanation:
The pair of dispersed phases and dispersing media that can never form a colloid is gas and gas (e). In colloids, the dispersed phase particles are evenly spread throughout the dispersion medium, which could be a solid, liquid, or gas. However, when two gases mix, their particles are so small that they always form a homogeneous mixture or solution, not a colloid. For instance, when you mix oxygen and nitrogen gases in the air, they form a solution, not a colloid.
To address similar questions, the phases of matter where molecules can change their positions include liquids and gases, and for the context of this question, plasma is omitted, but it would be included if we considered all four states of matter. Particles in a solid are unable to move freely due to the strong intermolecular forces holding them in place.
If you have a substance with strong intermolecular forces, a high melting point, and resistance to compression, that substance would be a solid. These properties describe the behavior of solid matter, where particles are packed together and held by strong forces.