A solution is a homogeneous mixture where the solute is uniformly distributed within the solvent. Let’s analyze the given options:
- a) Solids settle in the bottom of the beaker after being left to sit: This describes a suspension, not a solution. In a suspension, particles are large enough to settle out over time.
- b) Solute and solvent cannot be differentiated: This is a correct description of a solution. In a true solution, the solute particles are so small that they do not settle out and cannot be distinguished from the solvent.
- c) Two samples differ when taken from the same beaker: This would indicate a heterogeneous mixture, not a solution. In a solution, any sample taken from the mixture should be identical in composition.
- d) Chunks are suspended in a fluid: This describes a suspension or a colloid, not a solution. In these mixtures, particles are larger and can be seen suspended in the medium.
Therefore, the correct answer is b) Solute and solvent cannot be differentiated, as this best describes a solution.