A pure chemical substance that consists of only one type of atom is called a(n):

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

Answer: (D)

Verified step by step guidance

1. Understand the definitions of the given terms: a molecule is two or more atoms chemically bonded together, which can be the same or different elements.
2. A compound is a substance formed when two or more different types of atoms chemically bond together in fixed proportions.
3. A mixture consists of two or more substances physically combined, not chemically bonded, and can be separated by physical means.
4. An element is a pure chemical substance made up of only one type of atom, which cannot be broken down into simpler substances by chemical means.
5. Since the question asks for a pure substance consisting of only one type of atom, the correct term is 'element'.