Molecules that tend to move from an area of high concentration to an area of low concentration are called solute molecules. This movement is driven by the concentration gradient, the difference in concentration between two areas.

Here's a breakdown:

* Solute: The substance that is dissolved in a solvent (like sugar in water).

* Concentration: The amount of solute in a given volume of solution.

* Concentration Gradient: The difference in concentration between two regions.

* Movement: Solute molecules tend to move from a region of high concentration to a region of low concentration to even out the distribution.

This movement is known as diffusion, a passive process that doesn't require energy. Think of a drop of food coloring in water: the dye molecules spread out until they are evenly distributed throughout the water.

Let me know if you'd like more detail on diffusion or any other related concept!