Timeline of atomic discoveries

Timeline of Atomic Discoveries

1803

Atomic Theory of Dalton

1896-1898

Discovery of Radioactivity

1897

Electron Discovery

1904

Thomson's Model

1911

Rutherford's Model

1913

Bohr's Model

1926

Quantum-Mechanical Model

1920s-1930s

Development of Quantum Mechanics

John Dalton proposes his atomic theory, suggesting that all matter is made up of small, indivisible particles called atoms.

Henri Becquerel, Marie Curie, and Pierre Curie discover radioactivity, the spontaneous emission of radiation from certain elements.

J.J. Thomson discovers the electron, a negatively charged subatomic particle, through his experiments with cathode rays.

J.J. Thomson presents his "plum pudding" model of the atom, where electrons are embedded within a positively charged sphere.

Ernest Rutherford proposes his nuclear model of the atom, suggesting that atoms have a small, dense nucleus surrounded by orbiting electrons.

Niels Bohr introduces his atomic model, which incorporates quantized electron orbits and explains atomic spectra phenomena.

Erwin Schrödinger, Werner Heisenberg, and others develop the quantum-mechanical model of the atom, which describes electrons as probability clouds rather than particles following specific paths.

Quantum mechanics emerges as a theoretical framework to describe the behavior of particles at the atomic and subatomic levels.