A brief timeline of modern atomic theory

A brief timeline of modern atomic theory ⚛

1803: John Dalton proposed the first modern atomic theory, stating that elements are composed of indivisible atoms that combine in fixed ratios to form compounds.

1897: J.J. Thomson discovered the electron, a negatively charged… pic.twitter.com/NWs98KbExB

— Physics In History (@PhysInHistory) February 3, 2024

1803: John Dalton proposed the first modern atomic theory, stating that elements are composed of indivisible atoms that combine in fixed ratios to form compounds.

1897: J.J. Thomson discovered the electron, a negatively charged particle within the atom, using a cathode ray tube. He proposed the plum-pudding model of the atom, where electrons are embedded in a uniform positive sphere.

1911: Ernest Rutherford performed the gold foil experiment and discovered the atomic nucleus, a dense and positively charged core of the atom. He proposed the nuclear model of the atom, where electrons orbit the nucleus at a large distance.

1913: Niels Bohr developed the planetary model of the atom, where electrons occupy discrete energy levels around the nucleus. He explained the emission and absorption spectra of hydrogen atoms using his model.

1926–present: The quantum mechanical model of the atom was developed by various scientists, such as Louis de Broglie, Erwin Schrödinger, Werner Heisenberg, and Max Born. This model describes the electrons as wave-like particles that occupy orbitals, which are regions of probability for finding the electrons.