Name the three sub-atomic particles of an atom.

Atom:

1. The smallest unit of matter that makes up a chemical element is an atom. Neutral or ionized atoms make up every solid, liquid, gas, and plasma.
2. Later on, with further studies, it was discovered that atoms can be broken down into smaller particles.
3. A subatomic particle is less than the size of an atom. An atom is made up of three subatomic particles: protons, electrons, and neutrons.

Electrons:

1. John Thomson in the year $1897$performed an experiment where he used two plates with opposite charges near the cathode rays.
2. When high voltage was provided, the cathode rays were diverted from the negatively charged plate and moved towards the positively charged plate.
3. Because opposite charges attract and the like charges repel, cathode rays were thought to be made up of negatively charged particles called as electrons.
4. Electrons are subatomic particles that travel around the nucleus of an atom. When electrons are withdrawn or gained from an atom, ions are created.
5. The charge of an electron is $-1.602\times {10}^{-19}$Coulombs, The mass of an electron is $9.109\times {10}^{-31}$Kg.

Protons:

1. Protons and neutrons, together known as nucleons, make up the nucleus of an atom.
2. When Ernest Rutherford was conducting a gold foil experiment in$1911$, he discovered protons for the first time.
3. Positive alpha particles were deflected when he projected alpha particles towards gold foil.
4. As a result, a proton exists in the nucleus, and protons are positively charged subatomic particles.
5. The amount of protons in an atom helps to identify its atomic number.
6. A proton has a mass of $1.676\times {10}^{-24}$Kg and a charge of $1.6\times {10}^{-19}$ Coulombs.

Neutrons:

1. James Chadwick discovered the neutron in$1932$.
2. In an experiment conducted by James Chadwick, the penetrating radiation emitted by a beryllium sheet was induced to fall on paraffin wax. The protons produced were thoroughly studied in an ionization chamber.
3. The interaction of this penetrating radiation with various other atoms was also investigated, leading to the conclusion that it is made up of uncharged particles.
4. He termed these neutral, non-charged particles neutrons.
5. They possess no charge like a proton or an electron.
6. The neutron determines an atom's isotope and stability.
7. A neutron has a mass of $1.676\times {10}^{-24}$Kg.

Therefore, an atom has three subatomic particles namely electron, proton, and neutron.