History of Atoms

By Abanks0311
  • 460 BCE

    Democritus

    Democritus
    First person to use the term "Atom". Also made the theory that the whole universe was made up of them.
    Atoms are indestructible and unchangeable.

  • Dalton

    Dalton
    Elements are characterized by the weight of their atoms.
    Atoms of the same element are identical.
    Atoms of different elements combine in whole number ratios.

  • Mendeleev

    Mendeleev
    Made the periodic table with atomic mass.

  • Goldstein

    Goldstein
    protons have an equal and opposite charge as an electron.

  • Thomson

    Thomson
    Nearly Empty tube.
    An electric charge is passed through the tube, Travels from cathode to anode.
    Discovered the negative charged particle: the electron.

  • Millikan

    Millikan
    Discovered the value for electron charge through the famous oil drop experiment.

  • Rutherford

    Rutherford
    The nucleus of the atom is a dense mass of positively
    charged particles.The electrons orbit the nucleus.

  • Bohr

    Bohr
    Electrons orbit the nucleus in orbits that have a set
    size and energy.The lower the energy of the electron, the lower the
    orbit.

  • Chadwick

    Chadwick
    Chadwick is credited with the discovery of neutrons.