That would be the individual atoms.
The smallest unit in an element is the atom.
The smallest identifiable unit of an element that retains the properties of the element is an atom.
The smallest unit of an element that maintains the properties of that element is the atom.
The atom is the smallest unit of an element that has all the properties of the element.
The smallest unit of a chemical element is the atom.
This smallest unit is the atom.
An atom.
An atom
"atom"
Atom
Atom
An atom.