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Democritus came up with the Atomic Theory concept.
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Saw the world and everything in it as endless motion of small, indivisible particles- “atomos”. Named the atom as the building block of matter.
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Columbus discoverd land in the new world which is now the Bahamas.
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The first settlement of North America takes place in St. Augustine, Florida
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The first printing press in America arrives.
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Lavoisier first outlined the Principle of Conservation of Mass. Said that one element could not change into another. Lavoisier’s concept of an element provided the foundation for Dalton’s atomism.
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The American Philosophical Society is founded in Philadelphia by Ben Franklin
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Ben Franklin discovers electricity.
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Proust proposed the law of constant composition, which states that the ratio by mass of the elements in a chemical compound is always the same, regardless of the source of the compound. Helps in the development of universal laws.
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Declaration of Independence is signed by members of Congress.
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Washington is elected to be president.
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Says mass is an isolated system and will remain constant and that matter can neither be created nor destroyed. Lavoisier's concept of an element provided the foundation for Dalton's atomic theory.
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States that a given chemical compound always contains the same proportion by mass of its constituent elements. Discovered by Proust. Helps in the development of universal laws.
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Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass
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States that elements consist of tiny particles called atoms. All atoms of an element are the same and have the same mass. Provided further reason to believe that atoms are the building block of matter by providing the weight of careful chemical measurements.
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Augustus Jackson, an African American confectioner, created multiple ice cream recipes, and he invented a superior technique to manufacture ice cream.
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Gold is discovered in California. People form all overe the contry flood into California, followed by people form all over the world. It brought many people to America looking for money, and started the settelement of the west.
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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.
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Alexander Graham Bell sucessfully tests the telephone with his assistant. It revolutionizes communication due to it ease of use and more efficient to use than the telegram or previous methods of communication.
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Thomas Edison officially creates the first pratical electrically powered light bulb. This changed the world because it now allows for industrial processes to continue into the night due to the greater amount of light output compared to a candle. Workers can now work anytime of day.
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Studied "canal rays" and found they were associated with the proton H + .
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Tubes with all the air sucked out of them would give off a florescent light when high voltage was pumped into them. Led to the discovery of the electron by J.J Thompson
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Max Planck Theory states that the energy of each quantum is equal to the frequency of the radiation multiplied by the universal constant: E=f*h, where h is 6.63 * 10E-34 Js.
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The first time in hstory that a machine is made that powers itself for flying. Orville and Wilbur Wright successfully started a major revolution in flying technologhy that was to affect the way we move.
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Devised a mathematical method of calculating
the size of atoms and molecules. -
Rutherford fired Alpha particles at a sheet of gold foil. He found that most passes through the foil but some bounced off. Proved Thomson’s raison bread experiment wrong and helped discover the nucleus.
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Oil drop experiment determined the charge (e=1.602 x 10 -19 coulomb) and the mass (m = 9.11 x 10 -28 gram) of an electron.
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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.
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Using x-ray tubes, determined the charges on the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus". This work was used to reorganize the periodic table based upon atomic number instead of atomic mass.
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Developed an explanation of atomic structure that underlies regularities of the periodic table of elements. His atomic model had atoms built up of sucessive orbital shells of electrons.
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Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom.
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Using alpha particles discovered a neutral atomic particle with a mass close to a proton. Thus was discovered the neutron.
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Conducted experiments verifying that heavy elements capture neutrons and form unstable products which undergo fission. This process ejects more neutrons continuing the fission chain reaction.
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Terrorist Hijack 4 planes in the U.S.Two Planes crash into the Twin Towers. One Crashed into the Pentagon and the other crashed into a empty field in Pinnslyvania..
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Studied radiations emitted from uranium and thorium and named them alpha and beta.
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Studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre also discovered the radioactive elements polonium and radium.
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Used a CRT to study "canal rays" which had electrical and magnetic properties opposite of an electron.