Final answer:
When water and clay are mixed and left undisturbed, clay settles at the bottom, and clear water remains on top because the clay does not dissolve in water, forming a suspension.
Step-by-step explanation:
When water and clay are mixed, shaken, and then left undisturbed for 2 hours, you can conclude that C. Clay settles at the bottom while water remains on top. This happens because clay, composed largely of fine particles of silt, does not dissolve in water. Instead, it forms a heterogeneous mixture known as a suspension. Over time, gravity causes the heavier clay particles to settle at the bottom, resulting in a layer of clear water above the sedimented clay. This process is similar to how sand settles at the bottom of a glass of water when left undisturbed. Thus, the clay and water will separate into distinct layers after sufficient time has passed.