Atom diagram

The Atomic Theory... Awesome? I THINK YES!

  • Period: to

    Mordern Times

  • Joseph Proust

    Joseph Proust proved that the relative qualities of the elements that make up a chemical compound are constant. He proposed a law of constant composition whcih helps us identify whether matter is a pure substance or a homogeneous mixture.
  • Additional Event 1

    Thomas Jefferson is elected presifdent of the United States.
  • John Dalton

    John claims that atoms are small particles that cannot be destroyed. He also claims that there is no internal structure to an atom. This gave us a foundation to discover the structure of an atom.
  • Additional Event 7

    Souther troops in the United States open fire on Fort Summer beginning the civil war in the U.S.
  • Additional Event 2

    Over 100,000 people rush across Oklahoma to claim land out of the six million acres of former Cherokee land.
  • Henri Becquerel

    Henri made the accidental discovery of radioactivity through the fog emitted from uranium salt atoms. This helps scientists understand how radioactivity is formed and why it occurs.
  • JJ Thompson

    This man discovered the electron. He made a model called the "Plum Pudding Model". He beleieved that electrons stuck together in a big blob of positive charge. It is described like chocoalte chips sticking to a glob of dough. This discovery helps scientists understand what makes ions ions. This also enables us to further understand the structure of an atom.
  • Max Planck

    Discovered a new fundamental consatant (Planck's Consatant) which is used to calculate energy of a photon. This became the basisi of quantum theory, and later helped Einstein and Niels Bohr with their research.
  • Additional Event 9

    The electric typewriter is invented during this year.
  • Ernest Rutherford

    Ernest discovers a nucleus that is small and dense. He finds that the nucleus is positively charged and that electrons move around the nucleus. This give scientists a better picture of what an atom actually looked like.
  • Additional Event 3

    The Titanic sinks in the Atlantic Ocean while traveling to New York.
  • Neils Bohr

    Bohr created a model of an atom in which the electrons moved in orbits in a circle around the nucleus of the atom. He believed that each orbit had a fixed distance and that electrons could lose or gain energy by changing orbits. This helped us understand that the energy of an electron can change depending on its orbit.
  • Robert Millikan

    Robert was born in 1868. He did experiments to try and determine the amount of charge carried by an electron. His values for the mass and charge of an electron are extremely similar to what is accepted today. His Values: Electrons carry one unit of negative charge and mass= 1/1840 of a hydogen atom. This gave later scientists a basis on what the values would be for the mass and charge of an electron.
  • Louis de Brogile

    Brogile proposed that electrons have similar properties of waves. Later experimental evidence supports his claim. This idea pointed scientists in the right direction as far as the study of electrons went. This idea also showed possible connections with energy and matter (All energy is light, and light moves in waves).
  • Werner Heisenberg

    Werner published his theory of quantum mechanics. He wrote about only what can be observed of the radiation emitted by the atom. This gave us a basis on how radiation is emitted from an atom.
  • Erwin Schrondinger

    This man developed different mathematical equations to help in the description of the motion of all of the electrons inside of the atom. His work helps later scientists think of the electron cloud model.
  • James Chadwick

    He confirmed the discovery of the neutron in 1932. He confirmed that neutrons were subatomic particles with no charge, and that the mass of a neutron is nearly equal to the mass of a proton. This allows us to better understand isotopes.
  • Additional Event 8

    1933 is considered the worst year of the Great Depression.
  • Additional Event 6

    Japan attacks Pearl Harbor
  • Additional Event 5

    Al Capone dies in his mansion located in the Palm Islands from complications of syphillis.
  • Additional Event 4

    The beloved Marilyn Monroe is found dead this eveninig sometime after ten o'clock at night.