Question

Pure substances are classified as:

• A. elements and compounds
• B. elements and mixtures
• C. compounds and mixtures
• D. molecules and mixtures

Answer 1

The correct option is A elements and compounds

Substances that are made of only one type of atom or only one type of molecule are called pure substances.

They are classified as elements and compounds. An element is a pure substance that is made from a single type of atom. For example, element sodium (Na) is composed of only sodium atoms. A compound is a pure substance formed when atoms of two or more elements chemically combine with each other in a fixed proportion. For example, water is a compound that is composed of only water molecules.