Which term specifically refers to a substance made up of atoms of only one kind?

Which term specifically refers to a substance made up of atoms of only one kind?

• A. Pure substance
• B. Molecule
• C. Element
• D. Compound

Answer: (C)

Main idea: a substance made up of atoms of only one kind is an element. An element fits this because it consists entirely of identical atoms. A pure substance can be either an element or a compound, but the clue points to a single kind of atom, which identifies an element. A molecule is two or more atoms bonded together and can be made of the same kind of atom (like O2) or different kinds (like H2O). A compound is formed from two or more different elements chemically combined, so it does not meet the “one kind of atom” condition. Hence, the best term is element.

Main idea: a substance made up of atoms of only one kind is an element. An element fits this because it consists entirely of identical atoms. A pure substance can be either an element or a compound, but the clue points to a single kind of atom, which identifies an element. A molecule is two or more atoms bonded together and can be made of the same kind of atom (like O2) or different kinds (like H2O). A compound is formed from two or more different elements chemically combined, so it does not meet the “one kind of atom” condition. Hence, the best term is element.