Chem Project
Category: Autre
mise à jour avec succès: 27 sept. 2017
Alyssa George, Riley Gloeckl, Grace Bair, Sonja Hebestreit
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Created byAlyssa George
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Les événements
Aristotle (322 BC) - no matter how many times you cut the same matter in half you would still have the same matter just smaller piecesDemocritus (400 BC) - ancient Greek philosopher, central figure in the development of the atom and of the atomic theory of the universeEnrico Fermi (1942)Murray Gell-Mann (1964)Glen Seaborg (1951)Glen Seaborg (1941)Lise Meitner, Hahn, Strassman (1938)James Chadwick (1932)Paul Dirac (1932)Schrodinger (1930)Robert Boyle (1688) - Boyle’s law, describes the relationship between absolute pressure and volume of gasJohann Becher and George Stahl (dominated during the 1670s through 1790s) - the Phlogistic theory- when you burned something it lost phlogiston in the air. A problem of the theory resulted in different masses when metals were burned. The problem was fixed by assigning negative masses to phlogistons.Antoine Lavoisier (1742) - He proposed the Combustion Theory which was based on sound mass measurementsJoseph Priestley (1774)- discovered oxygenLaVoisier (1788) - Law of Conservation of Mass: matter can not be created or destroyed.Proust (1794) - Law of Definite Proportions: a pure substance will always contain the same elements, combined in the same proportion for mass.Joseph Gay-Lussac (1808) - announced the Law of Combining Volumes... He showed that at the same temperature and pressure, two volumes of hydrogen gas reacted with one volume of oxygen gas to produce two volumes of water (as a gas).John Dalton (1830) -proposed an “atomic theory” with spherical solid atoms based upon measurable properties of massAmedeo Avogadro (1811) - equal volumes of gases, under the same conditions, have different massesMichael Faraday (1832)- studied effect of electricity on solutions: 1) Electrolysis - the splitting of molecules with electricity
2) Developed law of electrolysisJ. Plucker (1859) - built one of the first gas discharge tubes (“cathode ray tube”)Dmitri Mendeleev (1869) - put the elements into 7 groups with similar properties and discovered the Periodic LawJames Clerk Maxwell (1873) - published physical and mathematical theories of the electromagnetic fieldSir William Crookes (1879) - discovered cathode rays have properties of: traveling in a straight line from the cathode, cause glass to fluoresce, impart a negative charge they touch, are deflected by electric fields and magnets to suggest a negative charge, cause pinwheels in their path to spin indicating the have mass.E. Goldstein (1886) - Used CRT to study “canal rays” which had electrical and magnetic properties opposite of an electron.G.J. Stoney (1894)- proposed that electricity was made from electronsWilhelm Roentgen (1895) - rays that are coming from the CRT not deflected by a magnetic field called “X Rays”Henri Becquerel (1896) - While studying the effects of x rays on photographic film, he discovered some chemicals spontaneously decompose and give off very penetrating rays.J.J. Thomson (1897)- use a CRT to calculate the charge to the mass ratio of an electron = 1.759 x 10 8 coulombs/gramsJ.J. Thomson (1897)- observed canal rays and realized the are connected to the proton H+Rutherford (1898)- studied radiations emitted from uranium and thorium, he named this alpha and betaMarie Curie (1898)- studied uranium and thorium, called their spontaneous decaying process “radioactivity”, discovered the radioactive elements polonium and radium with her husbandSoddy (1900)- observed spontaneous disintegration of radioactive element into variants he called “isotopes” or totally new elements, he discovered “half-life”, and made initial calculations on the amount of energy that is released during decayMax Planck (1900)- used the idea of a quanta to explain hot glowing matterHantaro Nagaska (1903) - postulated a “saturnian” model of an atom with flat rings revolving around a positively charged particleAbegg (1904) - discovered that inert gases had a stable electron configuration which led to their chemical inactivityPhilipp Lenard (1904) - He described atoms as mainly empty space filled with fast moving neutral particles, he called dynamites, were made of a heavier positive particle joined with a negative electronAlbert Einstein (1905) - published famous equation e=mc^2Han Geiger (1906) - developed an electronic device to “click” when hit with alpha particlesR.A. Millikan(1909) - Oil drop experiment that determined the charge and mass of an electronErnest Rutherford (1911)- He used the alpha particles as atomic bullets, probed the atoms in pieces of thin gold foil. Established that the nucleus was very dense and very small and positively charged. He also assumed that the electrons were located outside of the nucleusH.G.J. Moseley-(1914)- used and x ray tube to determine the charges on most nuclei in most atoms, He wrote the atomic number of an atom is the number of protons the have in the nucleus, this work was used to recognize the periodic table is based on the atomic number not the atomic mass.Aston (1919)- discovered the existence of isotopes through the use of spectrographNiels Bohr(1922) - developed an explanation and model of an atomic structure and underlies regularities of the periodic table of elementsDe Broglie (1923)- discovered electrons had a dual nature similar to both waves and particles.Heisenberg (1927) - described atoms in a formula connected to the frequencies of spectral lines, proposed Principle of Indeterminacy- you can not know both the position of a particle or the velocity of the same particleCockcroft/ Walton (1929) - built an early linear accelerator and bombarded lithium with protons to produce alpha particlesSome
event
happenedJohn DaltonAristotleMarie CurieAlbert EinsteinGlenn SeaborgThe Manhattan ProjectNiels BohrDmitri MendeleevDemocritusErnest Rutherford
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