What characterizes a saturated solution?

A saturated solution is characterized by the presence of equilibrium between the dissolved solute and any undissolved solute. This means that in a saturated solution, the amount of solute that can be dissolved in the solvent at a given temperature has been reached, and any further addition of solute will not dissolve. Instead, it will remain in solid form, leading to a dynamic balance where the rate of solute dissolving equals the rate at which it comes out of solution.

Therefore, the defining feature of a saturated solution is this state of equilibrium with undissolved solute, which is crucial in understanding concepts such as solubility limits and the behavior of solutions in general. The other options do not accurately describe a saturated solution, as they either misrepresent its properties or confuse it with other types of solutions. For instance, a saturated solution is not able to dissolve more solute (contrary to the first option), is not limited to room temperature, and does not inherently prevent crystal formation but rather allows for the formation of crystals when the saturation point is exceeded.