Final answer:
A pure substance is made of only one kind of matter and has definite properties. This is true.
Step-by-step explanation:
A pure substance is made of only one kind of matter and has definite properties. This statement is true. A pure substance can be an element, which consists of only one type of atom, or a compound, which consists of two or more types of atoms. Elements and compounds are both examples of pure substances. For example, oxygen gas (O2) and sodium chloride (NaCl) are pure substances.