Which statement accurately describes the relationship between a pure substance and a mixture?

Which statement accurately describes the relationship between a pure substance and a mixture?

• A. A mixture has a uniform composition; a pure substance contains two or more substances.
• B. A pure substance has a uniform composition; a mixture has a variable composition.
• C. A pure substance has a uniform composition; a mixture contains two or more substances.
• D. A pure substance can always be separated into simpler substances by physical methods.

Answer: (C)