The Atomic Theory Timeline

  • John Dalton

    John Dalton
    The Atomic Theory was proposed by John Dalton, He stated these things in his theory; All matter is composed by atoms. Dfferent atoms have different types of atoms. Atoms cannot be made or destroyed. All atoms of the same element are identical and chemical reactions occur when atoms are rearranged.
  • JJ Thompson

    JJ Thompson
    JJ discovered the electron. Thompsons experiments provided the first evidence that atoms are made of even smaller particles.
  • Marie Curie

    Marie Curie
    Marie Curie discovered Radium and Radioactivity.
  • Ernest Rutherford

    Ernest Rutherford
    Ernest Rutherford discovered the nucleus and all of an atoms positive charge is concentrated in its nucleus. He came to this conclusion because of the results of his gold foil experiment. He found out that most if an atom is empty space.
  • Niels Bohr

    Niels Bohr
    Niels Bohr made an atomic model that shows the atom as a small positivley charged nucleus, surrounded by orbiting electrons. He was first to discover that the electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbi determines the properties of an element.
  • Erwin Shrodinger

    Erwin Shrodinger
    Erwin used mathematical equations to describe the likelihood of finding an electron in a certain position.
  • James Chadwick

    James Chadwick
    James Chadwick proved the existence of neutrons, He established that atomic number is determined by the number of protons in an atom.
  • Electron Cloud Model

    Electron Cloud Model
    The Electron Cloud Model is an atom model where electrons are no longer particles moving around the nucleus in a fixed orbit. It has been found that we can only describe electron locations within fuzzy boundaries or 'cloud'
  • George Zweig

    George Zweig
    George Zweig was one of the first two scientists who proposed the first theory of subtomic particles known as quarks. Quarks are the buliding blocks of which protons and neutrons are made.