Which of these statements is correct? a. particles in a suspension will settle out if left undisturbed. b. a solution is heterogeneous. c. a colloidal system does not exhibit the tyndall effect. d. the particles in a colloidal system are all the same size.

Blood. It is discrete cells in saline solutuion. The cells are free to move thru the plasma, or you wouldn't have blood flow, or oxygenation, and you would die. Blood is defined as liquid, not jello.

The other three are things not normally associated--water will fall from the sky as rain, for example, but is held in suspension in fog. Same with the salad oil in mayo. O.J. can be a suspension; easily separated by a filter, Or a colloid--depends if the pulp, if Any, is held in suspension or not. Usually, pulp will settle to the bottom, making that sample of Orange juice a suspension. At different temperatures, it acts differently. But, so does Fog. A colloid is something that normally shouldn't be as some of its molecules are too dense to normally "float" in suspension. Colloid means "glue".