Atomic Timeline

  • John Dalton

    John Dalton
    He experimented the atomic theory on solid conclusions not on pure chance. He formed the atomic theory, which states that all matter is composed of tiny, indestructible particles called atoms that are all alike and have the same atomic weight. He ame up with a model which concluded that atoms are solid, and are combined in ratios to form compounds which is the law of conservation and mass and law of constant. composition)
  • John Dalton

    John Dalton
    He discovered that a proton is a positively charged particle with a charge, equal and opposite to that of electron.
  • Michael Faraday

    Michael Faraday
    Studied the effect of electricity on solutions, coined term "electrolysis" as a splitting of molecules with electricity, developed laws of electrolysis.
  • J.J. Thomson

    J.J. Thomson
    His first experiment was the cathode ray experiment, which was to determine the charge to mass ratio of an electron. With this experiment, it showed that atoms could be broken down into smaller particles, where some had negative charges. He proved atoms weren't made from solid spheres.
  • Ernest Rutherford

    Ernest Rutherford
    He used the gold foil experiment, theorizing that some protons should pass through it. Instead, some protons passed through, others deflected and reflected. It came to be that the center of an atom is positive and an atom contains an empty space, which is the nucleus.
  • Niels Bohr

    Niels Bohr
    Came up with the Bohr's Model which states that electrons orbit the nucleus in shells, and can be bumped up to higher shells by an electron or photon of light (photons produce when electrons fall down). Described his electron work in energy levels.
  • James Chadwick

    James Chadwick
    He used alpha particles to discover a neutral atomic particle with a mass close to a proton. In this way, he discovered the neutron.
  • Murray Gell- Mann and George Zweigin

    Murray Gell- Mann and George Zweigin
    They founded quarks. They discovered that electron-proton scattering experiments indicated that the electrons were scattering off three point-like constituents inside the proton
  • Martin L. Perl

    Martin L. Perl
    He discovered that a lepton is alike to the electron, the carrier of electrical current.