Which of the following best describes a heterogeneous mixture?

• A. A substance composed of two or more elements chemically bonded in fixed proportions.
• B. A mixture in which the composition is uniform throughout and the individual components are not visible.
• C. A pure substance that cannot be separated into simpler substances by physical means.
• D. A mixture in which the components are not uniformly distributed and can be visually distinguished.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the definition of a heterogeneous mixture. It is a mixture where the components are not uniformly distributed, meaning you can see different parts or phases distinctly.
2. Step 2: Compare this with a homogeneous mixture, where the composition is uniform throughout and individual components are not visible.
3. Step 3: Recognize that a pure substance is made of only one type of particle and cannot be separated by physical means, which is different from a mixture.
4. Step 4: Identify that a substance composed of two or more elements chemically bonded in fixed proportions is a compound, not a mixture.
5. Step 5: Conclude that the best description of a heterogeneous mixture is one where the components are not uniformly distributed and can be visually distinguished.