Here are 5 words that come to mind when I encounter the word "atom":
Nucleus: The center of an atom that contains protons and neutrons.
Electrons: Negatively charged particles that orbit the nucleus of an atom.
Subatomic: Referring to particles that make up an atom, such as protons, neutrons, and electrons.
Atomic number: The number of protons in the nucleus of an atom, which determines its chemical properties.
Molecule: A group of atoms held together by chemical bonds, forming the smallest unit of a chemical compound.