Difference Between Molecule and Compound (With Table)

Every material is made up of atoms that are very small in size. The characteristics and properties of any material or element are determined by the atoms. Atoms include protons, electrons, and neutrons. Therefore molecules, compounds, and everything is related to the atoms as these all are made up of atoms.

Further, there are elements, matter, molecules, and compounds. The similarities between all of them are that they are made up of atoms, but still, they have different properties and functions because when two or more atoms combine, the chemical properties changes.

Molecule vs Compound

The difference between a Molecule and a Compound is that a Molecule is a group of at least two or more atoms that are bonded together with a chemical force, whereas a Compound is the group of chemically bonded Molecules of different elements. All compounds are, therefore, molecules, but not all molecules are Compound.

A molecule is formed when two or more atoms are combined with a strong chemical force, the structure of the molecule is not very definite, which makes it very unstable, and they can be either heteronuclear or homonuclear and have Ionic or Covalent Bond. To see molecule microscopes is required.

A compound is formed when two or more molecules of different elements together with a strong chemical force which has a proper shape and due to which is very stable and they are always made up of different elements and have Ionic or Covalent or Metallic bond. And it is very visible to a compound normally.

Comparison Table Between Molecule and Compound

Parameters of ComparisonMolecule Compound
MeaningA Group of 2 or more atoms is a molecule.A Group of Molecules of more than one different element is a compound.
RelationIt is not always a compound, for example, hydrogen.Compound are molecules always.
StructureIt doesn’t have a uniform structure and is unstable.The actual matter having a uniform structure and is stable.
VisibilityIt is very tiny and cannot be seen with the naked eye. Microscopes are required.It is easily visible with the naked eye.
ExampleOzone and oxygenBaking Soda and Salt 

What is Molecule?

A molecule is when an atom of the same type or different type joins together with chemical forces. The mass of the molecule is depending on the atom it is made up of. There are various types of molecules such as:

  1. Diatomic Molecules: it is a type of molecule when only two atoms of either the same or different elements are bonded together, such as Oxygen and Carbon Monoxide.
  2. Heteronuclear Diatomic Molecule: it is a type of molecule when only two atoms of the same elements combined, such as Hydrogen, Oxygen, and Chlorine.
  3. Homonuclear Diatomic Molecule: it is a type of molecule when two atoms of the different atoms combine, such as carbon monoxide, hydrochloric acid (HCl), and Hydrogen Fluoride.

Complex molecules: These are the molecules made up of carbon atoms that are bonded with other elements. For example, Sucrose, in which carbon atoms are bonded with Hydrogen and Oxygen.

Macromolecules: these are very large molecules; they are made up of nearly 1000 atoms bonded together, such as proteins.

Molecular Formula: it is a formula that represents the chemical proportions of atoms, numbers, and elements and specifically used for this purpose. For example, the molecular formula of Acetic Acid is CH3COOH.

What is Compound?

When two or more different elements bound together, it formed the Compound, for example, water, carbon dioxide, and many more. All compounds are molecules. There are mainly two types of compound:

  1. Molecular compounds: in molecular compounds, the atoms are bonded together with the covalent bonds, for example, water and carbon dioxide.
  2. Salts: in salts, atoms are bonded together with Ionic bonds, for example, Sodium Chloride and Ammonium Chloride.

Characteristics of Compound

  1. It has a definite mass and structure, unlike molecules and atoms, and is highly stable.
  2. When two or more types of molecules combine, their individual properties change, and they have new chemical properties as a compound.
  3. It is not possible to separate the constituents of compounds by any simple process.
  4. Its melting and boiling points are both fixed.
  5. It is always homogeneous.

Every compound has a different molecular formula, most common compounds and their molecular formula is:

  1. Alcohol: C2H6O
  2. Acetic Acid: C2H4O2
  3. Sulphuric Acid: H2SO4
  4. Ammonia: NH3
  5. Methane: CH4
  6. Nitrous Oxide: N2O 
  7. Salt: NaCl

Main Differences Between Molecule and Compound

  1. The molecule is when two or more than two atoms are bonded tighter together with a chemical force, whereas a compound is when two or more molecules are bonded tighter together with a chemical force.
  2. Every compound is made up of molecules. Therefore, every compound is a molecule, but it is not with the molecule. Every molecule is not always a compound.
  3. The compound has a definite structure, and therefore it is more stable, but the molecule doesn’t have any definite structure. Therefore, it can be unstable.
  4. A molecule is so tiny in size that it cannot be seen easily with naked eyes. Special equipment is required for this, but the compound can be seen very easily.
  5. Molecules have an Ionic or Covalent bond, but compounds have an Ionic or Metallic or covalent bond.
  6. Molecules are either heteronuclear or homonuclear. Whereas compounds are made up of different elements always if there are the same elements, it is not a compound.


Therefore, it clears how both molecule and compound are related, but at the same time, both of them have different properties and characteristics depending upon their elements and the atoms. The mass of every molecule is different, which depends on each atom of which is made, and therefore the mass of every compound is different. 

Along with mass, other properties such as hardness, colour, state, etc., all of these depend on the atoms as the atom is the basic unit through which both molecule and compound are dependent. Examples of molecules that are also compounds are water, methane and greenhouse gas, etc.


  1. https://books.google.com/books?hl=en&lr=&id=n1mbd1SafcQC&oi=fnd&pg=PP1&dq=atoms+in+molecules&ots=p54cmruuS3&sig=PVlKW2ouLP58OWm3f7n0KU1M3j8
  2. https://www.sciencedirect.com/science/article/pii/S0899900709002251

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