Atom Model Over Time

Timeline created by zarrar007
  • Isaac Newton

    Isaac Newton
    Was one of the first people who understood the laws of motion and credited the fact that atoms were an infinite vacuum. He proposed the idea of a mechanical universe with solid masses in motion.
  • John Dalton

    John Dalton
    Came up with the idea of “atomic theory” with circular atoms based on properties of mass that were measurable. Today we can easily determine the element and its symbol based on Dalton’s work. He documented a journal of notes with the first use of symbols to represent the modern elements.
  • JJ Thomson

    JJ Thomson
    Studied “canal rays” and discovered that they were associated with the proton H+. With Thomson’s discovery, we know that electron clouds exist and how many electrons in each electron cloud.
  • Ernest Rutherford

    Ernest Rutherford
    Established that the nucleus was a very small and dense, positively charged particle. He also assumed that electrons were located outside the nucleus.
  • Niels Bohr

    Niels Bohr
    Developed an explanation for atomic structure that followed the periodic table. More understanding of the atom’s structure and the radiation was produced from his work.
  • James Chadwick

    James Chadwick
    Discovered using alpha particles, that a neutral atomic particle has a mass close to a proton. Thus a neutron was discovered. With the discovery of a neutron, scientists today are able to break up Uranium 235 and create atomic bombs.