Which of the following is a solution?

• A. Liquid mercury
• B. Pure water
• C. Salt water
• D. Oil and water mixture

Answer: (C)

Verified step by step guidance

1. Understand the definition of a solution: A solution is a homogeneous mixture composed of two or more substances where the solute is uniformly distributed within the solvent.
2. Evaluate each option to see if it fits the definition of a solution:
3. Liquid mercury is a pure element in liquid form, not a mixture, so it is not a solution.
4. Pure water is a single substance without any solute dissolved in it, so it is not a solution.
5. Salt water is a mixture where salt (solute) is dissolved uniformly in water (solvent), making it a homogeneous mixture, which qualifies as a solution.
6. An oil and water mixture is heterogeneous because oil and water do not mix uniformly, so it is not a solution.