What is the smallest particle of an element?

The smallest particle of an element is an atom. An atom consists of a nucleus made up of protons and neutrons, surrounded by electrons. Atoms retain the essential properties of the element they represent and cannot be broken down into smaller units without losing their identity as that particular element.

In contrast, a molecule is formed when two or more atoms chemically bond together. Molecules can consist of atoms of the same element or different elements combined. A compound, similarly, is a type of molecule that consists of two or more different elements bonded together in a fixed ratio, and like molecules, it also represents a combination rather than a single element.

The term "element" refers to a pure substance that cannot be broken down into simpler substances by chemical means; it encompasses one or more atoms of the same type but does not specify the smallest unit. Therefore, while all of these terms are related to chemistry and elements, the atom is the fundamental building block that uniquely defines an element.