Colorado Esthetician Written Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

All matter is composed of atoms. Atoms are the basic building blocks of all matter and are made up of protons, neutrons, and electrons. Elements are pure substances made up of only one type of atom, while molecules are made up of two or more atoms bonded together. Protons are subatomic particles found within the nucleus of an atom. In this context, atoms are the correct answer as they are the fundamental units of matter.