if a solution is contanimated with a chemical that causes a larger amount of solid, opaque particles floating in the solution, would the absorbance read too high or too low, and why?

The absorbance will be too high. Think ab out it. If opaque particles are in the solution, light can't be transmitted as well since it can't shine through the opaque material; therefore, the A will be too high. In fact, that is the basis for a method called nephelometry in which the light reflected from the particles of a suspension are directed onto a photocell at right angles to the beam of light and that photocell measures the reflected light.