Which statement best describes how compounds differ from elements?

• A. Elements are always gases, while compounds are always solids.
• B. Compounds consist of two or more different elements chemically bonded together, while elements contain only one type of atom.
• C. Compounds have variable composition, but elements have fixed composition.
• D. Compounds can be separated by physical means, whereas elements cannot.

Answer: (B)

Verified step by step guidance

1. Understand the definition of an element: An element is a pure substance that contains only one type of atom, characterized by a fixed composition and unique properties.
2. Understand the definition of a compound: A compound is a pure substance formed when two or more different elements are chemically bonded together in a fixed ratio.
3. Recognize that compounds differ from elements because compounds contain multiple types of atoms chemically combined, whereas elements contain only one type of atom.
4. Note that compounds have a fixed composition (definite ratio of elements), not a variable one, and cannot be separated by physical means but only by chemical means.
5. Conclude that the best description is that compounds consist of two or more different elements chemically bonded together, while elements contain only one type of atom.