A Brief History of Chemistry (http://examcenter.blogspot.com/2010/12/chemistry-degrees.html)
By drsnyder
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Alchemy is disproven and ceased to be practiced on a wide-scale (http://www.etftrends.com/2010/11/physical-gold-etfs-go-head-head/)
Boyle InformationDeath of AlchemyThe belief in Alchemy (transforming cheap metals into gold) is accurately disproved by the book, "The Skeptical Chemist", by Robert Boyle. In this, Boyle states that elements are substancees that cannot be separated into simpler components by chemical methods (exactly what alchemy is ). Thus, this early form of Chemistry ceases to be considered realistic and is justified by Boyle's statements. -
Charles Augustin de Coulomb creates Coulumb Law (http://www.sparknotes.com/chemistry/bonding/ionic/section1.html)
Coulomb Law Coulomb BiographyFrench scientist Charles Augustin de Coulomb conducted experiments and he concluded that given two particles separated by a certain distance, the force of attraction or repulsion is directly proportional to the product of the two charges and is inversely proportional to the distance between the two charges. This is known as Coulomb's law, and Charles did other experiments involving the attraction between particles. -
John Dalton's Atomic Theories and Model Made (https://podcast.punxsy.k12.pa.us/groups/weiblewiki/wiki/75938/)
Date and TheoryAtomic TheoriesJohn Dalton concluded that all atoms are indivisible and indestructible, chemical reactions are rearrangements of atoms, and that all atoms of an element are identical in their mass and properties. These important theories along with his new atomic model were significant in the advancement of chemistry. -
Eugene Goldstein discovers the Proton (http://reich-chemistry.wikispaces.com/422-003+Big+Time+Line+Project+ANDREW+M.+AND+KEVIN+D.+BIG+TIME+LINE)
GoldsteinGoldstein discovers protons by using a tube filled with hydrogen gas. He finds that the positive particle has a charge equal and opposite to the electron. It also has a mass of 1.66E-24 grams or one atomic mass unit. The positive particle is named the proton. -
Wilhelm Roentgen discovers X-Rays (http://www.howstuffworks.com/x-ray.htm)
X-RaysRoentgen accidentally discovered x-rays while researching the glow produced by cathode rays. Roentgen performed his research on cathode rays within a dark room and during his research, he noticed that a bottle of barium platinocyanide was glowing on a shelf. He discovered that the rays that were causing the fluorescence could also pass through glass, cardboard and walls. The rays were called x-rays. -
J.J. Thomson (http://www.kentchemistry.com/links/AtomicStructure/JJThompson.htm)
Thomson 2Thomson 1Thomson placed the Crookes' tube within a magnetic field. He found that the cathode rays were negatively charged and that each charge had a mass ratio of 1.759E8 coulombs per gram. He concluded that all atoms have this negative charge and he renamed the cathode rays electrons. His model of the atom showed a sphere of positively charged material with negative electrons stuck in it. Thus he discovered the presence of electrons in the atom. -
Robert Millikan discovers mass of the electron (http://www.nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html)
Millikan electron massMillikan discovered the mass of an electron by introducing charged oil droplets into an electrically charged field. The charge of the electron was found to be 1.602E-19 coulombs. Using Thomson's mass ration, Millikan found the mass of one electron to be 9.11E-28 grams. this helped scientists understand the relative size of the electron to the proton. -
Ernest Rutherford concludes that atom is mostly empty space (http://www.iun.edu/~cpanhd/C101webnotes/modern-atomic-theory/rutherford-model.html)
Rutherford Atomic ModelRutherford sent a radioactive source through a magnetic field. Some of the radioactivity was deflected to the positive plate; some was deflected to the negative plate; the rest went through the magnetic field without deflection. Thus, there were three types of radioactivity: alpha particles (+), beta particles (-) and gamma rays (neutral). From this research he modified Thomson's atomic model to one that had a nucleus of protons, quickly moving electrons moving around it but mostly empty space. -
Niels Bohr's constructs more accurate Atomic Model with neutrons (http://csep10.phys.utk.edu/astr162/lect/light/bohr.html)
Bohr's ModelBohr's TheoryBohr constructed a more accurate Atomic Model, now containing the discovered nuetrons and explaining the orbits of the electrons. He concluded that electrons had "stationary " orbits that remained the same and that each orbit had a certain energy associated with it. These ideas although not entirely accurate helped progress the Atomic Model.
