What term describes substances that cannot be broken down by chemical means?

• A. Elements
• B. Mixtures
• C. Compounds
• D. Solutions

Answer: (A)

Elements are substances that cannot be broken down by chemical means. They are made of only one type of atom, and chemical reactions rearrange or form new substances but don’t split an element into simpler substances. To break an element apart would require nuclear changes, not chemical ones.

Mixtures, on the other hand, are combinations of substances that can be separated by physical methods. Compounds are formed when elements bond chemically in fixed ratios, and they can be decomposed into their constituent elements by chemical reactions. Solutions are homogeneous mixtures where a substance is dissolved in a solvent.

So, the term for substances that cannot be broken down by chemical means is elements.