History of the atom

By Brianna Amanda
  • 460 BCE

    Democritus

    Democritus
    He developed the concept of the 'atom'.

  • Dalton

    Dalton
    He created the very first atomic theory. Each element is made up of particles called atoms.

  • JJ Thomson

    JJ Thomson
    He showed that the atom was made of even smaller things. Electrons orbit in circles within a sphere of positive charge.

  • Ernest Rutherford

    Ernest Rutherford
    He showed that atoms have (+) particles in the center and are mostly empty space. He discovered protons and nucleus.

  • Niels Bohr

    Niels Bohr
    He proposed that electrons move around the nucleus in specific layers or shells.

  • Edwin Schrodinger

    Edwin Schrodinger
    Described electrons as waves with their probable location viewed as a cloud and introduced a mathematical model of the atom.

  • James Chadwick

    James Chadwick
    Discovered the existence of neutrons, the neutral particle that shares the nucleus with the positively charged proton.