Molecule refers to a covalently-bonded compound.
Formula Unit refers to an ionically-bonded one.
Sodium chloride is a compound; a compound has a chemical formula (or a formula unit) not a chemical equation. The formula unit of sodium chloride is NaCl.
chemical formula
A formula unit is the chemical formula for a compound that can be used in balancing a stoichiometric equation. As this is the lowest possible combination of atomic combination, it is a formula unit.
Molecule
This is the chemical formula (empirical formula) or the formula unit of this compound.
CaCO3 is achemical compound and contains three different elents, calcium carbon and oxygen. It is ionic and the chemical formula is the formula unit.
The chemical formula for aluminium sulfide is Al2S3.
This chemical formula is BaSO4.
the answer is : A MOLECULAR FORMULA
Yes, it is correct - NaCl is a formula unit of sodium chloride; ionic compounds hasn't a true chemical formula.
NaCl is the chemical formula unit of sodium chloride. MgO is the chemical formula of magnesium oxide.
Symbols are the chemical symbols of elements.Number are the number of a specific atom in the molecule or formula unit. For example: Na2SO4- Na, S, O are the chemical symbols of sodium, sulfur and oxygen- 2 is the number of sodium atoms in the formula unit; 4 is the number of oxygen atoms in the formula unit