Final answer:
A mixture where large particles settle unless stirred, is a suspension, a heterogeneous mixture with particle sizes over 1000 nanometers.
Step-by-step explanation:
A mixture where the particles in a solvent are so large that they settle out unless the mixture is constantly stirred or agitated is known as a suspension. Suspensions are heterogeneous mixtures where the particle size is generally over 1000 nanometers, and these particles are visible or with a magnifying glass. Unlike a solution, the dispersed particles can be separated from the dispersion medium by filtering. An example of a suspension is a mixture of dirt and water, which appears cloudy and the dirt particles will settle if not continuously stirred.