There are two definitions that can answer particulate identity at its singular unit. If the given is a pure element, the smallest particle retaining identity would be the individual atom (or diatomic molecule in some gases as in O2). If the substance is a molecular compound such as water, its smallest identifying unit would be a single H20 molecule.
An Atom
If the substance is an element, the smallest will be an atom. If it is a compound, then that would be a molecule.
The smallest part of any chemical element that can exist is an atom of that element. The smallest part of a chemical compound that can exist is a molecule of that compound.
If the substance is an element the answer is an atom. If the substance is a compound the answer is a molecule.
An atom is the smallest particle of an element that still has the chemical characteristics of that element
An atom, these include protons, neutrons and electrons. The number of these smaller particles is what distingushes one atom of an element for another. For example, an atom of oxygen has 8 protons, neutrons, and electrons while a hydrogen atom has 1 proton neutron and electron
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.
Molecules are the smallest particles of a substance.
If the substance is an element, the smallest will be an atom. If it is a compound, then that would be a molecule.
An atom
The smallest part of any chemical element that can exist is an atom of that element. The smallest part of a chemical compound that can exist is a molecule of that compound.
The atom.
Element
The smallest particle of an element is called an atom.
A molecule if it is a compound, an atom if it is an element and a formula unit if it is an ionic crystal.
A molecule is the smallest part of a compound that still retains the properties of said compound. As the atom is the smallest particle of an element into which it can be divided and still retain all the properties of that element, the molecule is the atom's analog for a compound.
For a substance the term is molecule, for an element the term is atom.
If the substance is an element the answer is an atom. If the substance is a compound the answer is a molecule.