What is the Difference Between Atoms and Molecules

Difference between atoms and molecules

Are you just curious or have you got an assignment that has left you wondering what the difference between atoms and molecules is? Well, Atoms and molecules are two very familiar words and are sometimes used interchangeably by the uninitiated.

In this article, firstly we will discuss what are atoms and molecules and after that, we discuss the difference between atoms and molecules.

What are Atoms and Molecules?

An atom is the basic unit of an element. An atom consists of a nucleus, surrounded by one or more electrons.

Both electrons are negatively charged. The nucleus is positively charged and has one or more particles known as protons and neutrons.

An early model of the atom was first developed by the physicist Ernest Rutherford in 1912. He was the first to postulate that atoms are like mini solar systems, except that the attractive force is not due to gravity, but by opposing charges. 

Characteristics of atoms

  • An atom contains electrons, protons, and neutrons.
  • The center of the atom is always a positively charged proton or positive charge.
  • All atoms are electrically neutral.
  • Many theories were postulated to prove the charge of an atom.
  • An atom of the same element has the same number of protons and neutrons.
  • The size of an atom is known by the size of its radius.

A molecule consists of a group of two or more atoms that form the smallest noticeable unit into which a substance can be divided and still retain the composition and properties of that substance.

In 1926, French physicist Jean Perrin received the Nobel Prize in physics for proving, conclusively, the existence of molecules. He did this by calculating Avogadro’s number using different methods.

Characteristics of Molecules

  • They are very small in size.
  • They have space between them. 
  • They are in constant random motion.

Differences Between Atoms and Molecules

MeaningThey are tiny particles of an element that can or cannot occur freely.A molecule is a set of atoms that come together by a bond. Also, they are the smallest unit of a compound.
ExistenceThey may or may not exist freely.They exist in a free state.
ContainsIt contains a nucleus (proton, and neutron) and electron.It contains two or more different or identical elements that bonded together.
ShapeThey have a spherical shape.They have a triangular, linear, or angular shape.
VisibilityNot visible to naked eyes and also not to a magnifying microscopeNot visible to naked eyes but are visible through a magnifying microscope
ReactivityThey are highly reactive and subject to certain exceptionsIt is comparatively less reactive.
BondIt has a nuclear bond.It has a covalent bond.

Atom is the basic unit of of any element, whereas a molecule is the smallest particle of the compound.

Atoms may or may not exist independently whereas molecules exist independently.

In atoms, molecules make up atoms whereas in molecules atoms form the molecule.

Atoms might or might not have matter properties while molecules have matter properties.

Examples of atoms are hydrogen, oxygen etc.

Examples of molecules are H2 and O2 etc.

Atoms can be grouped into many kinds, whereas molecules are of only two types – homoatomic molecules and heteroatomic.

Atoms don’t have bonding whereas molecules have intermolecular forces and intramolecular forces.


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