Which statement correctly distinguishes an element, a compound, and a mixture?

• A. An element is a substance composed of multiple atoms, a compound is a single type of atom, and a mixture is a pure substance.
• B. An element is a pure substance made of one type of atom, a compound is two or more elements chemically bonded, and a mixture contains two or more substances not chemically bonded.
• C. An element is always a compound; a mixture is the same as a solution.
• D. An element is a mixture of atoms; a compound is a random combination of substances.

Answer: (B)

The main idea is how each type is defined by what it’s made of and how its parts are held together. An element is a pure substance made of one type of atom. It can exist as single atoms or as molecules that contain only that same atom (like O2 or H2), but it is still just one kind of atom. A compound forms when two or more elements chemically bond in a fixed ratio, creating a new substance with properties different from the starting elements; it can be broken down into elements only by chemical changes. A mixture is a combination of two or more substances that are not chemically bonded, so each component keeps its own properties and can be separated by physical methods, with no fixed proportion.

This description fits the correct statement because it clearly matches the definitions just described. The other options mix up what elements, compounds, and mixtures are—for example, suggesting elements are made of multiple atoms in all cases, or that mixtures are pure substances, or that a mixture is the same as a solution.