Answer:
An atom
Step-by-step explanation:
Atom is the smallest indivisible part of an element that retains its chemical identity. An atom contains the protons, neutrons and electrons, which are collectively called SUBATOMIC PARTICLES.
These particles ensure that the chemical identity of an element is maintained. For example, Chlorine has an element has an atom made up of 17 protons, 17 electrons and 18 neutrons. Therefore, chlorine atom is the smallest part of the chlorine element (Cl) that have all properties of that chlorine element.