Structure Of The Atom

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Matters are made of tiny particles called an atom. Atom is made of three particles; electron, proton and neutron. These particles are called fundamental particles of an atom or subatomic particles.

Electron (e^–) - Electron is denoted by ‘e’ and is a negatively charged particle.

Proton (p⁺) - Proton is denoted by ‘p’ and is positively charged particle.

Neutron (n) – Neutron is denoted by ‘n’ and is a neutral particle.

Discovery of Proton: Ernest Goldstein in 1886 discovered the presence of new radiation in gas discharge tube even before the identification of electron. He called these rays of Canal rays. His experiment led to the discovery of proton.

Discovery of the electron: In 1897; J.J Thomson, a British physicist, proposed that atom contains at least one negatively charged particle. This particle named as an electron.

Discovery of Neutron: In 1932 J. Chadwick discovered another subatomic particle called neutron. Neutron is present in the nucleus of all atoms.