Check out this amazing Timeline on Atomic History!
Philosopher Democritus thought that all matter is composed of indivisible elements.
John Dalton proposed each chemical element consists of a single type of atoms that could not be destroyed. This marked the official beginning of the atomic theory.
Amedeo Avogadro law made it possible to accurately estimate the atomic mass of an element. This also made a clear distinction between atoms and molecules.
Robert Brown observed dust particles floating in water, moving randomly for no known reasons.
J.J. Thomson discovered the electron. He believed atoms could be divided.
J.J. Thomson released his Plum Pudding model of the atom.
Albert Einstein postulated the Brownian motion was due to the movement of water molecules.
Jean Perrin provided experimental confirmation for Einstein’s observations. Additionally, Perrin’ observations enabled him to estimate the size of water molecules and atoms as well as their quantity in a given value.
Ernest Rutherford disproved the plum pudding model J.J. Thomson in and creates the Rutherford model which resembles a planetary model.
Niels Bohr proposed the Bohr model. This model stated that electrons only orbit the nucleus, also according to his model, the electrons couldn’t spiral into the nucleus, but could bound between energy levels.
Frederick Soddy described isotopes, atoms that contains different numbers of neutrons.
Erwin Schrodinger described how electrons move in a waveform using Schrodinger’s equation.
Paul Dirac proposed anti-particles.
Carl Anderson discovered the anti-electron (positron).
James Chadwick discovers the neutron completing the atomic model.
Otto Hahn and his assistant Fritz Strassmann discovered nuclear fission of heavy elements.
Lise Meitner theoretically explain Hahn’s and Strassmann’s discovery.
Glenn Seaborg synthesized 6 transuranium elements and changed the layout of the periodic table.
The first combat atomic bomb is used in Japan launching the a nuclear era making the atoms famous around the world.
At Obninsk, Russia the first nuclear power plant produced commercial electricity.
Emilio Segre and Owen Chamberlain detected the anti-proton.