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Difference Between Molecules and Compounds

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Molecules are the smallest building blocks that form the matter around us. They are the simplest particles that carry the properties of matter. Molecules are joined together to form the Compound. A molecule is the smallest unit of matter formed by joining various atoms together whereas the compounds are the matter that we see around us. The water that we see around us is a compound that is made up of water molecules. The molecules of water are represented as H2O.

Let’s learn more about Molecules, Compounds, and Differences between Molecules and Compounds in this article. 

What are Molecules?

Molecules are made up of one or more atoms that are held together by covalent bonds. Atoms can be represented as circle shapes with a nucleus in the center, surrounded by one or more concentric circles representing the shells in which the electrons surrounding the nucleus of the atom are located, and markings indicating the electron. 

 A molecule is the smallest unit of measurement that a substance can be divided into while still remaining the same substance. It is made up of two or more atoms that are chemically bonded together.

Types of Molecules

Molecules can be categorised into various categories as,

Monoatomic Molecule: Molecules containing only one atom is called monoatomic molecules. Examples are He (Helium), Ne (Neon), etc.

Diatomic Molecule: Molecules containing two atoms are called diatomic molecules. Examples are O2 (Oxygen Gas), Cl2 (Chlorine Gas), etc.

Polyatomic Molecule: Molecules containing more than two atoms are called polyatomic molecules. Examples are NH3 (Ammonia Gas), CO2 (Carbon Dioxide Gas), etc.

Examples of Molecules

A molecule is the smallest unit of the compound which individually tells us about the components of the compound. Various examples of molecules are,

H2O (Water)

Water is the most fundamental molecule which we observe in our daily life. It has one oxygen and two hydrogen atom and its structure is discussed in the image below,

Structure of Water

NH3 (Ammonia)

Ammonia is the first molecule which was mass-produced on the industrial level. It has one Nitrogen and three hydrogen atom and its structure is discussed in the image below,

Structure of Ammonia

CH4 (Methane)

Methane is the most important molecule to study the catenation property of carbon. It is the most basic organic compound. It has one Carbon and four hydrogen atom in its structure and its structure is discussed in the image below,

Structure of Methane

What are Compounds?

Compounds are a group of different atoms and different elements which unite together by a chemical bond. The chemical bond can be of three types, either covalent, ionic or metallic.

Similarly, it is important to remember that all compounds are molecules but not all molecules are compounds. Moreover, we only categorize heteronuclear molecules as compounds. However, the same is not the case with homonuclear molecules.

Remember that water’s chemical formula is H2O. Water is composed of two hydrogen atoms and one oxygen atom in this note. When two different elements combine, a new substance known as water is formed. 

Compounds are substances formed by the combination of two or more types of elements.

Atoms in a compound are chemically connected and thus cannot be easily separated. Similarly, carbon dioxide has the chemical formula CO2 and is made up of two elements: carbon and oxygen. Table salt (NaCl), chalk (CaCO3), and water are some other examples of compounds (H2O).

Types of Compounds

Compounds are classified into two different categories namely,

  • Molecular Compounds
  • Ionic Compounds

Molecular Compounds

Molecular compounds are all the general compounds which represent the molecular formula of the compound. Examples of molecular compounds are water, carbon dioxide, etc.

Ionic Compounds

Compounds formed by the electrovalent bond between two separate ions (Cations and Anions) are called Ionic compounds. Examples of ionic compounds are Sodium Chloride (NaCl), Potassium Chloride (KCl), Calcium Chloride (CaCl2), etc.

Learn more about, Chemical Formula of Common Compounds

Difference Between Compounds and Molecules

The basic difference between the compounds and molecules is shown in the image added below,

Difference Between Compounds and Molecules

The table added below shows the differences between Molecules and Compounds.

Differentiating PropertyMoleculeCompound
DefinitionMolecules are groups of two or more atoms that are held together by chemical bonds.Compounds are formed when two or more different elements are united chemically in a fixed proportion.
RelatednessAll molecules are not considered compounds.All compounds are made up of molecules.
StructureThey are groups of atoms that are bonded by a strong force.They are actual matter in their complete shape.
Visibility Molecules are not seen with the naked eye.Compounds can be easily seen with the naked eye.
StabilityMolecules can be stable or unstableCompounds are generally stable as it has a physical form
ExampleExamples of a molecule are Cl2, H2, etc.Examples of the compound are Sodium Hydroxide, Water, etc.

Read More,

FAQs on Molecules and Compounds

1. What is Difference between Molecules and Compounds?

The major difference between molecules and compounds is that molecules are very small they are generally not visible to human eyes where as compound are visible to human eyes also molecule can be either stable or unstable whereas compounds are generally stable.

2. What is Difference between Molecular Formula and Empirical Formula?

Empirical formula is basic formula for any compound whereas, molecular formula, can be counted as a multiple of the empirical formula. It is based on the precise number of atoms present in the compound for each type. For example, if the compound’s empirical formula is C3H8, its molecular formula could be C3H8, C6H16, and so on.

3. Is H2O a Molecule or a Compound?

H2O is a Compound in H2O two hydrogen atoms and one oxygen atom combines in a definite ratio to form a water molecule.

4. What are Types of Compounds?

Generally, compounds are categorised into two categories,

  • Ionic Compound: Example, NaCl, CaCl2, etc
  • Molecular Compound: Example, H2O, CO2, etc.

5. What is a Compound?

A compound is a substance that is formed by joining different types of elements in a fixed proportions. They are present in all the matter around us. A compound is formed by molecules. Some examples of compounds are, Water, Common Salt, Acetic Acid, etc.

6. What is a Molecule?

A molecule is formed by joining two or more atoms together. They are formed by atoms joint together by chemical bond. These molecules forms the base of each compounds, example of compounds are, NaCl, CaCl2, etc.

Last Updated : 19 Oct, 2023
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