Mixtures whose particles are smaller than those in heterogeneous mixtures and larger than solutions are called colloids.

Here's why:

* Solutions: The particles in a solution are so small (atoms, ions, or molecules) that they are evenly distributed and don't settle out. They are also transparent, meaning you can see through them.

* Heterogeneous mixtures: The particles in a heterogeneous mixture are large enough to be seen and can settle out over time.

* Colloids: Colloids fall in between. The particles are larger than those in solutions but smaller than those in heterogeneous mixtures. This means they are not evenly distributed and will scatter light (the Tyndall effect), but they won't settle out easily.

Examples of colloids: milk, fog, paint, blood, and jello.