Which statement best describes the relationship between elements and compounds?

• A. Elements and compounds are both pure substances, but compounds cannot be broken down into simpler substances.
• B. Compounds are substances formed by the chemical combination of two or more elements.
• C. Elements are mixtures of different compounds.
• D. Elements are formed when compounds are separated by physical means.

Answer: (B)

Verified step by step guidance

1. Understand the definitions: An element is a pure substance consisting of only one type of atom, while a compound is a pure substance formed when two or more different elements chemically combine in fixed proportions.
2. Recognize that elements cannot be broken down into simpler substances by chemical means because they are the simplest form of matter with unique atoms.
3. Know that compounds can be broken down into their constituent elements by chemical reactions, but not by physical means.
4. Identify that elements are not mixtures; mixtures contain two or more substances physically combined, whereas elements are pure substances.
5. Conclude that the best description is: 'Compounds are substances formed by the chemical combination of two or more elements,' because this accurately reflects the nature of compounds and elements.