Question

Smallest unit that consists of at least one atom

A. Protons

B. Neutrons

C. Electrons

D. Molecules

Answer 1

An atom is made of three parts:

1. Protons
2. Neutrons
3. Electrons

Those three parts are all PART of an atom.
They are NOT one whole atom.

Whole atoms can combine together, to form molecules.

Molecules are made of atoms. Every molecule has at least two atoms.