Occupational English Test (OET) Reading Practice Exam 2025 - Free OET Reading Practice Questions and Study Guide

The term that best describes a solid that forms and settles out of a liquid mixture is "precipitate." When certain chemical reactions occur, particularly those that involve the mixing of two solutions, a solid can form as a product. This solid, known as a precipitate, often becomes visible and can eventually settle at the bottom of the container, differentiating itself from the liquid phase above.

In the context of various mixtures, a precipitate indicates a change that often signifies that a chemical reaction has occurred, a crucial concept in chemistry. Other terms, such as "sediment," refer to solid particles that settle out of a liquid due to gravity but typically have a different context, such as being part of a natural process rather than a result of a reaction.

"Solution" refers to a homogeneous mixture where one substance is dissolved in another, while "suspension" describes a mixture where fine particles are dispersed throughout a liquid but not completely dissolved, and they may settle over time. Thus, the clarity and specificity of a "precipitate" in the context of chemical reactions make it the correct choice for describing a solid formed and settling from a liquid mixture.