What are Atoms Made of

Everything around us matter. The smallest part of a matter is an atom. For instance, a single pen we use to write is made up of million trillions of atoms. Now another question arises What are Atoms Made of. Let’s discuss it.

What are Atoms Made of

Atom is the basic unit of matter. Atoms are made of protons, neutrons, and electrons

  • Protons are located in the nucleus of an atom having positive electrical charge.
  • Neutrons are situated within the nucleus of an atom having no electrical charge.
  • Electrons are located in clouds outside nucleolus and have negative electrical charge.

What are Atoms Made of

  • The electron was discovered in cathode ray experiment.
  • Proton was discovered in the anode ray experiment
  • The neutron was discovered by James Chadwick in 1932. They were discovered through the nuclear reaction.

Must Read


  1. Anode rays, are also known as canal rays and were discovered by E. Goldstein.
  2. The specific charge of anode rays is not constant. It varies from particle to particle.
  3. The mass of one mole of a proton is 1.007 g.
  4. The charge on one mole of a proton is 96500 Coloumb or 1F.   


  1. The name electron was given by Stoney.
  2. The charge on the electron was determined by Millikan in the oil drop experiment.
  3. The mass of an electron and specific charge was calculated by J.J. Thomson.
  4. The mass of one mole of an electron is 0.55 mg and charge on one mole of an electron is 96500 Coloumb or 1 F.


  1. The neutron is slightly heavier than a proton.
  2. The mass of one mole of a neutron is 1.0087 g.
  3. The neutron is the heaviest fundamental particle and is least stable.
  4. Neutron disintegrates to electron, proton and neutrino.

Other Particles

In the modern era, the scientists have found other numerous particles other than electron, proton, neutron. Let’s have a look at a few of them.

  • Positron: It is the positive counterpart of an electron, discovered by Anderson. On combining with electrons, produce γ-rays.
  • Neutrino and antineutrino: These were discovered by Fermi in 1934. Their mass is negligible and has no charge.
  • π- mesons and μ– mesons: These were discovered by Yukawa. Their mass is in between that of electron and proton.

This is all about the basic – What are Atoms Made of.