Difference Between Atom and Compound (With Table)

Everything on this planet is made up of atoms and compounds, and this is the reason why they as structures are very important. Any object (living or non-living) that we use in our daily life, even our bodies, contains atoms. Atom bonds together to form molecules, compounds and hence form matter (solid, liquid, or gas).

In simple words, we would not have a functioning world or any object without atoms. If something is this common and important in our life, we should have some basic knowledge about it along with their differences.

Atom vs Compound

The main difference between an atom and compound is that an atom is the smallest particle unit of a matter which cannot be broken any further, whereas a compound is made up of two or more molecules( which are made up of atoms) of different elements (chemically bonded together).

An atom is the smallest unit/ building block of matter. All the solids, liquids, and gases consist of atoms (neutral or charged). Electrons, protons, and neutrons are the sub-atomic particles of an atom. An atom is very small in size – around 100 picometers. Each atom has a nucleus in its centre, and most of the atom’s mass is present in its nucleus.

A compound is a substance made up of one or more atoms as part of molecules. From two or more elements, a chemical bond keeps them held together. Depending on the structure and placement of the atoms, there are four types of compounds (bonds). Only a chemical reaction can change one compound to another substance when it interacted. They cannot be broken down by physical means.

Comparison Table Between Atom and Compound

 Parameters of Comparison




 An atom is the smallest unit or building block of any matter.

 A compound is a chemical substance made up of one or more molecules(made up of atoms) of different elements held together by a chemical bond.


 It is derived from a Latin word via the Greek word ‘atomos’ which means indivisible.

 The word compound is derived from an old French word ‘compoun’ taken from the Latin word ‘componere’ which means put together.


 Atoms are the smallest unit of a matter, so small that they cannot be divided or split any further.

 A compound in a chemical bond and can be broken into /divided to form a new and different substance by a chemical reaction.


 Atoms can be stable, isotopic, radioactive, etc. These are different types of atoms based on their charges.

 Compounds have four different types based on their bonds – covalent, ionic, metallic, and coordinated covalent bonds.


 neon(Ne), hydrogen(H), iron(Fe) etc are examples of atoms.

 NaCl (sodium + cholrine), H2O ( Hydrogen X2 + Oxygen) etc.

What is Atom?

An atom is the smallest unit/building block of any matter- living or not. All the solids, liquids, or gases are composed of atoms (charged or neutral). Without atoms, we would not have any matter functioning on this planet.

Atoms being the smallest unit particle, cannot be divided or broken down any further. The size of the atom is nearly 100 picometers. They consist of three subatomic particles – neutron (no charge), proton (+ charged), and electron (- charged). It has a nucleus in the middle that consists of 99.94% of atoms mass. The proton and neutrons are present in the nucleus (centre), and the electrons revolve in the shell/orbit present outside the nucleus.

An atom is neutral if the number of protons and electrons are equal. Charged atoms are called ions. An electromagnetic force keeps the electrons and protons attracted, and the nuclear force keeps the neutrons and protons attracted. Atoms as molecules come together in a bond to form compounds and elements. The atomic number is the number of protons in the nucleus, and atomic mass is the mass of an atom in a chemical element.  

Example; hydrogen (H), neon (Ne), etc.

What is Compound?

A compound is a chemical substance made up of many molecules (made of atoms) from more than one element held together by a chemical bond. There are chemical formulas that specify the number of atoms in each element.

There are four types of compounds based on their bonds –

  • Covalent bond – they hold the molecules together.
  • Ionic bonds – holds the ionic compounds together
  • Metallic bonds – holds the inter-metallic compounds together.
  • Coordinate covalent bond- holds together a few complexes.

A chemical reaction with another substance is done when you want to convert the compound into a different chemical. The bonds between atoms break and split. They then interact with the other atoms to form new compounds. Compounds are called pure substances as no physical change can separate the compounds.

It is made up of the same kinds of molecules, which are made up of two or more kinds of atoms. Compounds are considered to be homogeneous mixtures as they have a definite composition throughout. It can be heterogeneous only if it is present in two or more states (dry ice, etc.).

Main Differences Between Atom and Compound

  1. An atom is the smallest unit/building block of matter, whereas a compound is made up of the same molecules (made up of atoms) of different elements.
  2. Atoms are the smallest particle, and hence it is not divisible any further whereas compounds can be divided/ split through chemical reactions.
  3. An atom is made up of subatomic particles – protons, electrons, and neutrons, whereas compounds are made up of two or more molecules of different elements.
  4. Types of atoms are based on the charge – stable, isotopes, radioactive, etc., whereas types of compounds are based on the bonds – ionic bonds, covalent bonds, metallic bonds, etc.
  5. Neon (Ne) and hydrogen (H) are examples of atoms, whereas NaCl and H2O are examples of compounds.


Chemistry seems difficult to understand; all terms (atoms, mixtures, compounds) sound complicated but is important in our daily life. Everyone has a thing that is very important to them like. It is said that water is very essential for living, but all of this wouldn’t exist without the bonds and nature of everything under the branch of chemistry. The food we eat, the objects we use, the medications we take, and all others have chemistry and their components in them.


  1. https://books.google.co.in/books?hl=en&lr=&id=bAYV5sgcXrwC&oi=fnd&pg=PR10&dq=atoms&ots=IPwpylKnbR&sig=9FdwFqw5TfWg9q-eZnEx-Uq8KTM
  2. https://books.google.co.in/books?hl=en&lr=&id=uzEXBQAAQBAJ&oi=fnd&pg=PP1&dq=compounds&ots=pR6sAjjdrH&sig=Q3lGJ9kfx0nU7pVa9fGf-zEThy0