What is the smallest unit of an element?

The smallest unit of an element is an atom. An atom represents the fundamental building block of all matter and retains the properties of the element to which it belongs. Each atom is made up of a nucleus that contains protons and neutrons, surrounded by electrons that occupy various energy levels or shells.

Molecules are formed when two or more atoms bond together, meaning they contain more than one atom and cannot represent a single element. The nucleus, while critical to the structure of an atom, is not an independent unit; rather, it is a part of the atom itself. Electrons are subatomic particles found within the atom but do not constitute the atom as a whole and cannot independently represent an element. Thus, recognizing that the atom is the smallest unit that can exist as an element is crucial for understanding the fundamental components of matter.