In the classification of matter, which statement best describes the difference between an element and a compound?

• A. An element is always a mixture of substances, whereas a compound is always a pure substance.
• B. An element is a pure substance made of only one kind of atom, whereas a compound is a pure substance made of two or more different elements chemically bonded in fixed ratios.
• C. An element can be separated into simpler substances by chemical reactions, whereas a compound cannot be chemically separated.
• D. An element is made of molecules, whereas a compound is made of atoms that are not bonded to each other.

Answer: (B)