What is the smallest measurable unit of an element?

The smallest measurable unit of an element is an atom. Atoms are the basic building blocks of matter and the fundamental units that make up chemical elements. Each element on the periodic table is composed of atoms that have a specific number of protons, neutrons, and electrons. This atomic structure determines the properties of the element, defining how it interacts with other elements and compounds.

In the context of chemistry, other terms have different meanings. While a particle can refer to a very small piece of matter, it is not a specific term for elements. Molecules consist of two or more atoms bonded together, while compounds are substances formed from two or more different elements that are chemically bonded in a fixed ratio. Neither molecules nor compounds can be considered single units of an element. Thus, the atom serves as the fundamental, indivisible unit that retains the chemical characteristics of the element it represents.