Subatomic Particles

What are Subatomic Particles

Subatomic particles also called elementary particles are any of the various self-contained units of matter or energy which are the fundamental constituents of all the matter around us. Subatomic particles include electrons, which are the negatively charged, almost massless particles which nevertheless account for most of the size of the atom. It includes the heavier building blocks of the small yet dense nucleus of the atom, the positively charged protons and the electrically neutral neutrons. The field of subatomic particles has expanded vastly with the construction of powerful particle accelerators for studying the high-energy collisions of electrons, protons, and the other particles within the matter. In this article, we will take a look at what are subatomic particles, subatomic particles definition, and the discovery of subatomic particles.

Subatomic Particles in Nucleus

For quite a long time, it was believed that the atoms are the ultimate particles which matter is made of and that the atoms cannot be divided any further. The experiments conducted during the time of the latter half of the nineteenth century and the early years of the twentieth century revealed that the atom is not the only particle. The continued efforts of the scientists eventually led to the discovery of the subatomic particles.

The three primary subatomic particles which constitute an atom are shown below:

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Discovery of Atomic Particles

The discovery of the atomic particles is discussed here.

The limitations of Dalton’s atomic theory for explaining certain observations that formed the basis for the discovery of the electrons and protons. Further investigations then revealed the existence of the neutrons. The components of the atoms are known as subatomic particles and usually include the proton, the electron, and the neutron.

Nucleus of an Atom

The nucleus of the atom was discovered in the year 1911 by Ernest Rutherford, a physicist from New Zealand. In the year 1920, Rutherford proposed the name proton for the positively charged particles of the atom. He also theorized in which he said that there was a neutral particle within the nucleus, which James Chadwick, a British physicist and student of Rutherford's, was able to give the confirmation in the year 1932.

Virtually, all the mass of the atom resides in its nucleus. The protons and neutrons which make up the nucleus are approximately of the same mass (the proton, however, is slightly lesser) and have the same angular momentum or spin.

The nucleus is held together by the strong force, one of the four basic forces in nature. This force between the protons and neutrons overcomes the repulsive electrical force that would otherwise push the protons apart, according to the rules of electricity. Some atomic nuclei are unstable because the binding force varies for different atoms based on the size of the nucleus. These atoms will then decay into other elements, such as carbon-14 decaying into nitrogen-14.

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Subatomic Particles of an Atom

Let us now discuss the main subatomic particles. Given below is the subatomic particles list.


Protons and neutrons both together make up the nucleus of an atom and are therefore called nucleons. 

  1. Protons are the positively charged subatomic particles.

  2. The number of protons present in an atom equals the number of electrons in it.

  3. The discovery of protons was done by Ernest Rutherford.

  4. Protons can be produced through the removing of an electron from a hydrogen atom.

  5. The mass of the proton is 1.676 10-24 grams.

  6. The charge of the proton is + 1.602 10-19 Coulombs.


Electrons are the subatomic particles which revolve around the nucleus of the atom. These electrons can be lost from or gained by an atom to form the ions. Electrons of several different atoms come together to participate in the chemical bonding.

  1. Electrons are called to be the negatively charged subatomic particles

  2. Equal number of both the electrons and protons constitute in the atoms of all the elements.

  3. J. Thompson is known to be related to the discovery of electrons because he was the first person to calculate accurately the mass and the charge of an electron.

  4. The mass of an electron is negligible when it is compared to the mass of the proton. It is found to have a mass which is equal to (1/1837) times than that of the mass of a proton.

  5. The charge of an electron equals to -1.602 10-19 Coulombs.


Neutrons, along with the protons, make up the nucleons. Neutrons are named since they are neutral in nature. Unlike the protons and electrons, they do not have any charge.

  1. Neutrons are called as the neutrally charged subatomic particles.

  2. The masses of two different given isotopes of an element tend to vary because of the difference in the number of the neutrons of their respective nuclei.

  3. The neutron was discovered in the year 1932 by James Chadwick.

  4. Neutrons were discovered in an experiment in which a thin sheet of beryllium was allowed to bombard with the alpha particles.

  5. The mass of the neutron is 1.676 10-24 grams.

FAQ (Frequently Asked Questions)

1. Name the three subatomic particles of an atom. Give the difference between three subatomic particles.

If you have to name three subatomic particles of an atom, they are protons, electrons and neutrons. Protons are the positively charged particles, electrons are the negatively charged particles, and neutrons are electrically neutral, which means that they do not possess any charge. All three subatomic particles have different subatomic particles mass.

2. What are the charges of the subatomic particles?

The charges of all three subatomic particles are different. Since the proton is a positively charged particle, it has a positive charge. Electrons are electrically negative and therefore, have a negative charge. Neutrons, as their name suggests, is electrically neutral and hence has a neutral charge.