Which of the following is a mixture that has a uniform concentration throughout?

• A. A solution
• B. A heterogeneous mixture
• C. A colloid
• D. A suspension

Answer: (A)

Verified step by step guidance

1. Understand the definitions of the types of mixtures: A heterogeneous mixture has visibly different substances or phases, a colloid has particles dispersed throughout but not fully dissolved, a suspension has larger particles that settle over time, and a solution is a homogeneous mixture with uniform concentration throughout.
2. Recall that a homogeneous mixture means the composition is the same throughout the entire sample, with no visible boundaries between components.
3. Recognize that a solution fits this description because the solute particles are completely dissolved at the molecular or ionic level, resulting in uniform concentration.
4. Contrast this with heterogeneous mixtures, colloids, and suspensions, where the concentration or particle distribution is not uniform throughout the mixture.
5. Conclude that the mixture with uniform concentration throughout is a solution.