What is the smallest unit of an element?

The smallest unit of an element is the atom. An atom is the fundamental building block of matter and retains all the properties of that element. It is composed of subatomic particles, including protons, neutrons, and electrons.

Molecules, on the other hand, are formed when two or more atoms are chemically bonded together, making them larger than individual atoms. An ionic bond refers to the electrostatic attraction between positively and negatively charged ions, which is a type of interaction that occurs between atoms but does not define the smallest unit of an element. A compound consists of two or more different types of atoms that are chemically combined, which also makes it more complex than a single atom. Thus, the atom is appropriately identified as the smallest unit of an element, encapsulating its unique chemical properties.