What is the smallest particle that retains the characteristics of an element?

The smallest particle that retains the characteristics of an element is an atom. Atoms are the fundamental building blocks of matter and are the basic units of chemical elements. Each atom consists of a nucleus made up of protons and neutrons, surrounded by electrons, which define the chemical properties of the element. When considering different particles, while molecules consist of two or more atoms bonded together, they represent a combination of elements rather than a single element itself. Ions are atoms or molecules that have gained or lost electrons, resulting in a charge and thus altering their identity as a neutral element. Compounds are substances formed from two or more elements that are chemically bonded together. Because an atom is the smallest unit of matter that still exhibits the unique properties of its corresponding element, it is rightly identified as the answer.