an atom
an atom
An atom is the smallest particle of a substance.
An atom is the smallest particle of a substance.
Quarks are the smallest things in existence. A quark is an elementary particle.
atoms
It is a molecule of the substance.
Molecule
The smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms is a molecule.
Molecules are the smallest particles of a substance.
If it is an element, then the smallest particle that retains the characteristics of the element is an atom. If it is a diatomic element, then the smallest particle that retains the characteristics of the element is a molecule. If it is a molecular compound, then the smallest particle that retains the characteristics of the compound is a molecule. If it is an ionic compound, the smallest particle that retains characteristics of the compound is a formula unit.
Either an atom or a molecule, depending on the substance.
Atoms