What happens to the particles in a suspension over time?

In a suspension, particles are dispersed throughout a fluid, but they do not dissolve in it. Over time, these particles are subject to the forces of gravity. As a result, they tend to settle to the bottom of the container, creating a distinct layer and leaving a clear liquid above. This settling phenomenon occurs because the particles in a suspension are typically larger and denser than the liquid medium, making them unable to remain evenly distributed indefinitely.

In contrast, other options describe different behaviors that do not apply to suspensions. Some mixtures might remain uniformly mixed, but this applies more to solutions than suspensions. Other mixtures might involve components that dissolve or blend seamlessly into each other, characteristics not representative of suspensions where separation and settling are key features. Thus, the tendency for particles in a suspension to eventually settle out is a defining characteristic of this type of mixture, making it the correct choice.