Which term describes a chemical substance that cannot be broken down into simpler substances by chemical means?

• A. Compound
• B. Element
• C. Molecule
• D. Mixture

Answer: (B)

Verified step by step guidance

1. Understand the definitions of the terms given: an element, a compound, a molecule, and a mixture.
2. Recall that an element is a pure chemical substance consisting of only one type of atom and cannot be broken down into simpler substances by chemical means.
3. Recognize that a compound is a substance formed when two or more elements chemically combine and can be broken down into those elements.
4. Know that a molecule is the smallest unit of a compound or element that retains its chemical properties, but it may still be broken down if it is a compound.
5. Identify that a mixture is a physical combination of two or more substances that can be separated by physical means and is not a pure chemical substance.