What is the smallest unit of an element?

The smallest unit of an element is an atom. Atoms are the fundamental building blocks of matter and represent the identity of an element. Each atom consists of a nucleus, containing protons and neutrons, surrounded by electrons in specific energy levels. When atoms of the same element bond together, they can form molecules, but the individual atom is still the smallest unit that retains the distinct properties of that element.

Understanding atoms is crucial in the study of chemistry and biology, as they participate in forming compounds through chemical bonding and reactions. Molecules, compounds, and ions involve combinations or transformations of atoms, but they do not stand alone as the smallest representation of an individual element. For instance, compounds consist of two or more different atoms bonded together, while ions are atoms that have gained or lost electrons and carry a charge. Therefore, the clear distinction of atoms as the smallest unit of an element is fundamental to grasping the basic concepts in chemistry related to elements and their interactions.