The term for a substance that cannot be broken down into simpler substances by chemical means is the ______.

• A. compound
• B. mixture
• C. solution
• D. element

Answer: (D)

In chemistry, a substance that cannot be broken down into simpler substances by chemical means is an element. It is made of only one kind of atom and cannot be decomposed by chemical reactions into other substances. Compounds are formed from two or more elements bonded together and can be decomposed into those elements by chemical reactions. A mixture is a physical blend of substances not chemically bonded, and a solution is a homogeneous mixture where a solute is dissolved in a solvent; both can be separated by physical methods. Therefore, the term that fits is element.