Difference Between Molecules And Compounds (With Table)

Molecules and compounds are terms used in chemistry. Chemistry is a branch of science which deals with the study of matter, its properties, and composition. The terms are related to each other but molecules and compounds have very different properties. The basic differences between the terms are mentioned below.

Molecules vs Compounds

The main difference between molecules and compounds is that molecules are groups of atoms tethered together by chemical bonds while compounds are chemical substances that are formed by different types of elements united chemically in a definite proportion. Compounds are composed of molecular entities. All molecules are not compounds but all compounds are molecules.

A molecule is a group of atoms. These atoms are held together with each other with a force known as a chemical bond. They can be either home-neutral or heteronuclear. Molecules are not visible to the naked eye as they are tiny particles of matter. For example, N2 (Nitrogen), O3 (Ozone).

Compounds are composed of molecules. They are formed by two or more different types of elements, which are held together in a definite proportion chemically. Compounds are held together by strong forces called bonds like covalent bonds, ionic bonds, or metallic bonds. Examples, H2O2 (Hydrogen peroxide), CO (Carbon monoxide), and C6H12O6 (Glucose), etc.

Comparison Table Between Molecules And Compounds

Parameters of ComparisonMoleculesCompounds
DefinitionA molecule is formed when a group of atoms are held together with a force known as a chemical bond.Compounds are formed by two or more different types of elements, which are held together in a definite proportion chemically.
ExampleO2, O3, etc.NaCl, H2O, CH4, etc.
ElementsMolecules can be made of atoms of similar elements or different elements.Compounds have atoms of different elements.
VisibilityMolecules are not visible to the naked eye.Compounds are visible to the naked eye.
BondCan be held together by either a covalent bond or an ionic bond.Can be held together by either a covalent bond, ionic bond, or metallic bond.

What are Molecules?

A molecule is a group of atoms (a particle of matter) that are held together with a force known as a chemical bond. A molecule can consist of two or more identical atoms or two or more different atoms. Molecules mean extremely minute particles. There are different types of chemical bonds in chemistry. Molecules are held together by a bond. It can be a covalent bond or by ionic bond, mostly.

Electrically, a molecule is a neutral group of atoms. They lack electric charge and that’s how they are differentiated from ions.

The substances of life are all molecules. All the organic substances, the atmosphere, the water bodies are made up of molecules. However, there are many solid substances on earth that are not made of molecules. This includes bedrocks, soil, pebbles, rocks, and the core of the earth. According to researchers and scientists, these substances are made of chemical bonds, not molecules, at least not of identifiable molecules.

A molecule can be homonuclear or heteronuclear. Homonuclear means it consists of atoms of one chemical element only. Heteronuclear means the molecule consists of more than one chemical element. The science of molecules is known as Molecular chemistry if the focus is on chemistry and Molecular physics if physics is preferred.

What are Compounds?

Compounds are formed by two or more different types of elements, which are held together in a fixed and definite proportion chemically. Compounds are composed of more than one identical molecule or molecular entity, where a molecule is heteronuclear. A homonuclear molecule that is a molecule with atoms of one element only is not a compound.

There are millions of different chemical compounds. Depending on how the atoms are held together there are four types of compounds:

  1. Ionic compounds
  2. Intermetallic compounds
  3. Covalent compound
  4. molecules held together by co-ordinate covalent bonds

Compounds have different properties than that their component elements. When they are formed the elements lose their original properties and the compound forms its own property as a new substance. Compounds cannot be broken down into smaller forms by any physical means, they can be broken chemically.

There are many examples of Compounds. The list is endless. Some of the examples of the compounds are CH4 (Methane), C6H12O6 (Glucose), NaHCO3 (Sodium Bicarbonate), Etc. The compounds are presented using chemical formulas, named according to the AICTE standards.

The compounds are visible to the naked eye. Compounds are used by humans in their daily lives all the time, like table salt which is chemically known as Sodium chloride (NaCl).

Main Differences Between Molecules And Compounds

  1. A molecule is formed when one or more atoms are held together chemically. While compounds are formed when heteronuclear molecules are held together.
  2. All molecules are not compound although all the compounds are molecules.
  3. Molecules can be either homonuclear or heteronuclear. While compounds are made of heteronuclear molecules only.
  4. Molecules cannot be seen by the naked eye while compounds can be seen by the naked eye.
  5. Molecules can have either the covalent bond or ionic bonds. On the other hand, compounds can have either covalent bonds, ionic bonds, or metallic bonds.

Conclusion

Molecules are groups of atoms chemically bonded together. Molecules can be either homonuclear or heteronuclear. Homonuclear means the atoms of the same chemical element. For example, O 2 , that is oxygen. And heteronuclear means atoms of different chemical elements like H2O. Molecules cannot be seen by the naked eye.

Compounds are made of a group of heteronuclear molecules. All the compounds are molecules, though it is not true for vice versa. Covalent bonds, ionic bonds, or metallic bonds are the bonds by which compounds are held together. Compounds can easily be seen by naked eyes. For example, Sodium chloride (NaCl), Methane (CH4), etc.

In simple words, Molecules are groups of the same or different atoms and compounds are groups of different molecules.

References

  1. https://pubs.acs.org/doi/pdf/10.1021/ar00109a003
  2. https://www.jstor.org/stable/3571104
  3. https://books.google.com/books?hl=en&lr=&id=OAUPEAAAQBAJ&oi=fnd&pg=PR13&dq=organic+compounds&ots=zx6ZLXyK55&sig=td1gy_D9uFXgtN8s9BHBPBFxmtI
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2D vs 3D