What is the smallest particle of an element?

The smallest particle of an element is an atom. Atoms are considered the fundamental building blocks of matter, and each element is defined by its unique type of atom. Atoms consist of a nucleus made up of protons and neutrons, surrounded by a cloud of electrons.

Molecules, on the other hand, are formed when two or more atoms bond together, thus representing a larger assembly than a single atom. An ionic bond refers to the electrostatic attraction between charged ions, which also involves interactions between multiple atoms. Electrons are subatomic particles found within atoms, but they do not qualify as standalone particles of an element. Therefore, among the choices provided, the atom is recognized as the smallest unit that retains the chemical properties of that element.