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Vacuum Pump
http://www.rsc.org/chemsoc/timeline/pages/1645.html Otto von Guericke created the firtst vacuum pump. Its purpose was to demostrate the capacity of the atmosphere to do work. Through creating the vacuum, he also learned that the air remaining in the sphere was distributed evenly throughout the vessel. He proved the vacuum seal by taking away the air between two half sphere and showing that horse could not even pull them apart. -
Death of Alchemy
http://www.columbia.edu/itc/chemistry/chem-c2507/navbar/chemhist.html http://en.wikipedia.org The disproval of Aristotle's Four- Element Theory and the book "The Skeptical Chemist" lead to the end of earlier chemistry beliefs. This happened near the end of the 17th century. The purpose of alchemy was to clarify and anticipate the products of their chemical reactions, resulted in early conceptions of chemical elements and the first rudimentary periodic tables. -
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Disproving of the Phlogiston Theory
http://www.columbia.edu/itc/chemistry/chem-c2507/navbar/chemhist.html The exact days for the start and end are unsure because it took time to disprove the Phlogiston Theory. This theory stated that When a substance is burned, phlogiston was supposedly added from the air to the flame of the burning object. -
John Dalton
http://en.wikipedia.org Dalton was a English chemist, meteorologist and physicist. He is contributed with the idea of the atomic weight scale and the first atomic weight basis as H. This was called the atomic theory. -
The Proton
http://www.columbia.edu/itc/chemistry/chem-c2507/navbar/chemhist.html Eugene Goldstein descovered a positively charged partical that had a charge equal and opposite to the electron. He then named the partical a proton. A proton has the same number as electrons. -
J. J. Thomson
http://en.wikipedia.org Thomson is credited with the discovery of electrons and of isotopes, and the invention of the mass spectrometer. The idea of electrons was propose in 1897, while isotopes and mass spectrometer was proposed in 1912. -
Discovery of the Neutron
http://www.columbia.edu/itc/chemistry/chem-c2507/navbar/chemhist.html James Chadwick discovers the neutron. The neutron in found in the nucleus of a cell and has a neural charge. It has aproximitly to same mass as a proton. -
Ernest Rutherford
http://en.wikipedia.org Ernest Rutherford was known as the father of nuclear physics. This is because he discovered the concept of radioactive half-life and proved that radioactivity involved the transmutation of one chemical element to another. -
Niels Bohr
http://en.wikipedia.org Niels Bohr was a danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics. He is also well know for the Bohr model of the atom, which stated the theory that electrons travel in discrete orbits around the atom's nucleus. The shell model of the atom was also proposed by him. This is where the chemical properties of an element are determined by the electrons in the outermost orbit.
