Timeline

History of the Atomic Model

By Meerkat18
  • 440

    Democritus Discovers Atomos

    Democritus Discovers Atomos
    Around 440 BC, Democritus discovered atoms, or "atomos" by breaking up material into his pistol.

  • Dalton Refines the Atom

    Dalton Refines the Atom
    John Dalton, a British scientist, refined Democritus' theory. He found that atoms of the same element are exactly alike, and ones of different elements are different.

  • Thomson Discovers Electrons

    Thomson Discovers Electrons
    J.J. Thomson found that there are even smaller particles inside of an atom, what we now call electrons.

  • Rutherford Says Atoms are Mostly Empty Space

    Rutherford Says Atoms are Mostly Empty Space
    After two years of discovery, in 1911 Rutherford concluded that atoms are mostly empty space. He also said that there was a tiny spot of dense matter - a nucleus.

  • Bohr Makes it Modern

    Bohr Makes it Modern
    In 1913, Niels Bohr came up with what is very close to our current understanding of atoms. He said that the electrons were in orbit around the nucleus.