Question

the smallest particle of an element that retains the properties of that element is the

Explanation:

An atom is the fundamental unit of an element. It is the smallest particle that can exist independently and still retain the chemical properties of that element. Molecules are made up of atoms (for compounds, multiple types of atoms; for elements like \(O_2\), same - type atoms). But for an element in its simplest form (like a pure metal or a noble gas in atomic form), the atom itself is the entity that has the element's properties.

Answer:

atom