What is the smallest unit of an element known as?

The smallest unit of an element is known as an atom. An atom consists of a nucleus containing protons and neutrons, surrounded by electrons that orbit the nucleus. Atoms are the fundamental building blocks of matter, and they retain the properties of the element they represent.

In contrast, a molecule is formed when two or more atoms bond together, representing a combination of elements rather than the smallest singular unit of a specific element. A compound is a substance made up of two or more different elements that are chemically bonded in a fixed ratio, which again signifies a larger structure than a single atom. An ionic bond refers to the electrostatic attraction between charged ions, which occurs between atoms during the formation of compounds, rather than serving as a standalone unit.

Thus, the accurate term for the smallest unit of an element is indeed an atom.