History of the Atom

Timeline created by johnelhawi
In History
  • Period: May 17, 1000 to


  • Issac Newton

    The date is unknown for all of them (I couldn't find them) so I just put a random date Proposed a mechanical universe with small solid masses in motion.
  • John Dalton

    Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass.
  • Michael Faraday

    Studied the effect of electricity on solutions, coined term "electrolysis" as a splitting of molecules with electricity, developed laws of electrolysis. Faraday himself was not a proponent of atomism.
  • J. Plucker

    Built one of the first gas discharge tubes ("cathode ray tube").
  • Dimitri Mendeleev

    Arranged elements into 7 groups with similar properties. He discovered that the properties of elements "were periodic functions of the their atomic weights". This became known as the Periodic Law.
  • James Clerk Maxwell

    Proposed electric and magnetic fields filled the void.
  • Sir William Crookes

    Discovered cathode rays had the following properties: travel in straight lines from the cathode; cause glass to fluoresce; impart a negative charge to objects they strike; are deflected by electric fields and magnets to suggest a negative charge; cause pinwheels in their path to spin indicating they have mass.
  • E. Goldstein

    Used a CRT to study "canal rays" which had electrical and magnetic properties opposite of an electron.
  • GJ. Stoney

    Proposed that electricity was made of discrete negative particles he called electrons
  • Wilhelm Roetgen

    Using a CRT he observed that nearby chemicals glowed. Further experiments found very penetrating rays coming from the CRT that were not deflected by a magnetic field. He named them "X-rays".
  • Soddy

    Observed spontaneous disintegration of radioactive elements into variants he called "isotopes" or totally new elements, discovered "half-life", made initial calculations on energy released during decay.
  • Nagaoka

    Postulated a "Saturnian" model of the atom with flat rings of electrons revolving around a positively charged particle.
  • Ernest Rutherford

    Using alpha particles as atomic bullets, probed the atoms in a piece of thin (0.00006 cm) gold foil . He established that the nucleus was: very dense,very small and positively charged. He also assumed that the electrons were located outside the nucleus.
  • de Broglie

    Discovered that electrons had a dual nature-similar to both particles and waves. Particle/wave duality. Supported Einstein.
  • Schrodinger

    Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom.
  • Ernico Fermi

    Conducted the first controlled chain reaction releasing energy from the atoms nucleus.