In matter, the term heterogeneous is applied to which description?

• A. Uniform mixtures
• B. Pure elements
• C. Substances with uniform composition
• D. Mixtures with visibly different parts

Answer: (D)

This concept is the distinction between heterogeneous and homogeneous mixtures, based on whether the components are evenly distributed. In a heterogeneous mixture, the different substances are not spread uniformly and you can usually see separate parts with the naked eye. That’s why describing mixtures with visibly different parts best fits heterogeneous matter. The other options refer to uniform composition throughout—homogeneous mixtures or pure substances—where you wouldn’t be able to distinguish different components. So heterogeneous is used for mixtures with visibly different parts.