M.Ennulat+Time+Line+Project

__Timeline Project__ __Ancient Greece:__ Leucippus- Greek philosopher around 400 BCE He was one of the earliest of the philosophers of atomism which was the idea that everything is made up of indivisable and imperishable elements called atoms. Democritus-Greek Philosopher about 460 BCE- about 370 BCE - created a theory that there are various basic elements which always existed but can be rearranged into many different forms. - he also thought atoms had only several properties:size, shape, and weight. other properties, such as color and taste, are the result of complex interactions between the atoms

Aristotle- Greek Philosopher 384 BCE- 322 BCE - came up with the five elements: Fire- hot and dry Earth- cold and dry Air- warm and wet Water- cold and wet Aether- divine substance that makes up the stars and planets the four earthly elements has its natural place. When the elements are out of their natural place they have natural motion, requiring no external cause; so bodies sink in water, air bubbles up, rain falls, flame rises. The heavenly element has a circular motion. Peloponnesian War- 431-404 BCE Euripedes produces Medea in Athens- 431 BCE Construction of Temple of Athena Nike- 420-410 BCE __466-1700's:__ Galileo Galilei- Italian chemist 1564-1642 -Published the work, __Discourse of Floating Bodies__ in 1612 based on atomism. Robert Boyle- Irish chemist 1627-1691 -Created Boyle Law which states that for a fixed amount of gas kept at a fixed temperature, both entities will be inversely proportional. published in 1662 -Was one of the major figures in the rebirth of atomism. Mayflower Compact signed-1620 French and Iroquois Wars- 1640 Bacon's Rebellion in Virginia-1676 __1700-1800's:__ Sir Isaac Newton- English chemist 1643-1728 - made the law of gravitation that states that all objects with mass attract eachother. This is what keeps the planets in orbit. - he also described how universal gravitation worked which was what kept the moon orbiting aroun the earth. John Dalton- English chemist 1766-1844 -He calculated atomic weights from percentage compositions of compounds, using an arbitrary system to try to determine the atomic structure of each compound -//New System of Chemical Philosophy// was a book where he described his idea of elements and combinations of elements. It was published in 1827. This was his model of the elements Antoine Lavoisier- French chemist 1743-1789 - He established the Law of Conservation of Mass through experiments of burning phosphorus and sulfur into the air and proving that they weighed more than originally. This proved that in any chemical reaction, mass is conserved: Matter is neither created nor destroyed; only the form of the matter is altered. The Seven Years War- 1755 The American Revolution- 1775 The Storming of the Bastilles- 1789 __1800- 1875's:__ Wilhelm Conrad Roentgen- German chemist 1845-1923 - He dicovered a new kind of ray,X-rays, by covering the Hittorf-Crookes tube with cardboard and attached electrodes to a Ruhmkorff coil to generate an electrostatic charge. J.J. Thompson- English chemist 1856-1940 - He discovered the electron, the only thing smaller than an atom in 1897 - He created the plum pudding model where the atom has electrons, which Thomson still called "corpuscles," and were surrounded by a positive charge to balance the electron's negative charge, like plums surrounded by pudding. Washington D.C. becomes capital of USA- 1800 Napoleon defeated at Waterloo- 1815 Napoleon I's nephew crowned as Emperor Napoleon III- 1852 __1875-1915:__ Ernest Rutherford- chemist form New Zealand 1871-1937 -He discovered the atomic nucleus and developed a model of the atom in which electrons orbit around the central nucleus - In his Gold Foil experiment he discovered that most of the rays would pass through the gold foil and only a small percentage bounced back Henri Becquerel- French chemist 1852-1908 - Discovered there was a realtion between X-rays and naturally occurring phosphorescence - When he put uranuim salts, which phospherece in light, near photograohic plate, the plate fogged up. Dmitri Mendeleev-Russian chemist 1834-1907 - wrote __the Principles of Chemistry__ and published it in 1869 which had the 63 known elements organised into a table by their atomic mass Custer defeated at Battle of Little Big Horn- 1876 James Adams founds a hull house- 1889 USA defeats Spain in Spanish, American War- 1898 __1900-1915's__ Erwin Schrodinger- chemist 1877-1961 - He published in __Annalen der Physik__ the paper "//Quantisierung als Eigenwertproblem//" on wave mechanics and what is now known as the Schrödinger equation. In the paper he gave the wave equation for time independent systems, and that it gave the correct energy eigenvalues for the hydrogen-like atom. - His second paper solved the quantum harmonic oscillator, the rigid rotor and the diatomic molecule, and gave a new version of the Schrödinger equation. - His third paper showed the treatment of the Stark effect. -His fourth paper showed how to treat problems in which the system changes with time, as in scattering problems. -He created a revolution in quantum mechanics,physics and chemistry Marie Curie- Polish chemist, worked in France 1867-1934 - Discovered two new elements polonium, and radium -Developed methods for the separation of radium from the radioactive residues to be able to characterize it and the to study its properties. The Boxer Rebellion- 1900 First Nobel Prizes awarded-1901 Mount Pelée Erupts- 1902 __1915-1950's-__ Robert A. Millikan- American chemist 1868-1953 -He accurately determined the charge carried by an electron, using the "falling-drop method"; he also proved that this quantity was a constant for all electrons in 1910,thus demonstrating the atomic structure of electricity. Niels Bohr- Dutch chemist 1885-1962 -He came up with an explanation of the properties of the metals with the aid of the electron theory - Made a model of the atomic structure which he won a Nobel Prize for in 1922 - Came up with the liquid droplet theory where he beleived the nucleus of an atom was a lot like a water droplet - Wrote books including his theories such as //The Theory of Spectra and Atomic Constitution//, //Atomic Theory and the Description of Nature//, and //The Unity of Knowledge// Werner Heisenberg- German chemist 1901-1976 - He made the theory of quantum mechanics, in which he won a Nobel Prize for in 1932 - His theory resulted in the discovery of allotropic forms of hydrogen - His theory stated that we cannot always predict where an electron will be at a certain time or follow its orbit Armenian Genocide-1915 Pearl Harbour- 1941 Nuremberg Trials- 1946 electron cloud model-currently accepted model of the atom planetary model- based on the solar system, the nucleus is at the center like the sun, with the electrons orbiting like planets.

Small, spherical, indvisable model- the earlier model that shows that an atom is a sphere and cannot be divided into smaller pieces

__Bibliography http://scienceworld.wolfram.com/biography/Lavoisier.html http://www.chemheritage.org/classroom/chemach/periodic/dalton.htmlhttp://www.utm.edu/research/iep/d/democrit.htm http://www.timelineindex.com/content/select/1626/1023,820,1626__ http://nobelprize.org/nobel_prizes/physics/laureates/1903/becquerel-bio.html http://www.chemistry.co.nz/mendeleev.htmhttp://nobelprize.org/nobel_prizes/physics/laureates/1903/marie-curie-bio.htmlhttp://nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html http://nobelprize.org/nobel_prizes/physics/laureates/1922/bohr-bio.html