Fall.2008.MMA.Bancroft.Burchfeild.Timeline

= = = = =**If you want to research more content about the diet solution isabel de los rios free then visit** [|the diet source reviews]**.1.)** __Ancient Times (450 A.D And Years Prior)__=


 * [[image:reich-chemistry/chem3.JPG]]__Democritus__: Birth: 460** B.C**. Death:** 370 B.C
 * Place of Birth: Greece**
 * Discoveries/Ideas: "matter is made up of invisible indestructible pieces."**


 * Biography:** Democritus was a man who focus was that of Greek philosophy.As a philosopher hes ideas were of guess and thought rather than that of experiment. He along with other philosophers thought of the idea that all things are made of "matter" and that matter is made of tiny indestructible pieces called atoms. He did have unusual ideas about how different substances had different shaped atoms for example, liquids had round and big atoms, but he was on the right track at how different stages, (solid, liquid, gas), atoms are spread out and make different formations. This theory is often referred to as "atomism." Since Democritus's ideas were untested they are called theories. Still to this day Democritus was the first to understand the all things are made up of millions of other things, and the smallest unit of things is indestructible. It is surprising how close Democritus was to the actual properties and with no scientific equipment, or previous references.

__**Aristotle:**__ **Birth:** 384 B.C, Greece. **Death:** 322 B.C


 * Biography:** Aristotle was another early scientist who believed that all things were made of smaller things. Along with Democritus past references, he came up with a theory that all things are made of earth, wind, fire, and air. His knowledge and idea of self thought lead him to create what we know today as "scientific method" which along the way to fully discovering atoms has been one of the key equations. Like Democritus most of his work lacked testing and there was no "quantitative grasp" on how to properly define how everything combines as well as what is the basic unit of theses combinations.

This model was the earliest idea of what all things were made of earth water wind and fire. Early scientist such as Democritus and Aristotle as well as other people of the ancients ages believed all things were made up of a combination of these things. This idea was on the right track but not specified enough. Water, Wind, Fire and Earth and the combination of them was the basic concept of what all things are made of. All though some what in true, their early discoveries about atoms and combinations of element where later defined better and better understood by modern scientist as well as modern technologies.

Check out earth wind air and fire in action. http://www.youtube.com/watch?v=PmGu1wOqFGk

**Birth:** 341 B.C. **Death:** 327 B.C. **Place Of Birth:** Samos **Discoveries:** Developed the original scientific method Description: “all objects and events, including human lives, are in reality nothing more than physical interactions among minute indestructible particles. As they fall toward the center of the earth, atoms swerve from their paths to collide with each other and form temporary compound beings." This is a famous quote from Epicurus. He was not only a major contributor to the early study of atoms, but he also developed the original scientific method.
 * __Epicurus __**

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=**2) 1700-1800 **= = =

**Birth:** 1766 **Death:** 1844 **Place of Birth:** Cumberland, England **Discoveries:** Developed the theory that all elements are divisible into tiny particles called atoms. He believed that each atom in an element are identical, however, they are different from atoms in another element. Dalton’s atomic theory is the first quantitative theory ever advanced. Dalton is called the father of modern atomic theory partly because of his clear statement of that theory and partly because of his emphasis on atomic weights. Dalton made some of the most significant scientific breakthroughs of his time, but none of them were as significant as the atomic theory.  John Dalton was also the first person to compose a table of atomic weights. this idea has transformed to what we now know as the periodic table. He believed that atoms of different elements had different masses. He formed these masses into a organized table separating each element into its own specific category.
 * John Dalton **

**Birth:** August 26th, 1743 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Death:** 1794 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Place Of Birth:** Paris, France <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Discoveries:** Lavoisier's discovered that the total weight of the substances taking part in a chemical reaction remains the same before and after the reaction. He discovered this before the announcement of the law of conservation of mass. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Description: Lavusere’s major discoveries included the disproving of the phlogiston theory of combustion. Phlogiston was a substance believed to be emitted during combustion metals, before it was believed that a metal was composed of calx and phlogiston, and that burning resulted from the loss of phlogiston. Lavoisier,saw that it was physically impossible for anything to have negative weight. To dismantle this false theory Antoine Lavoisier introduced quantitative measurement to atomic science.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Antoine Lavusere **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Birth:** August, 20,1779 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Death:** August, 7, 1848 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Place of Birth:** Ostergotland, Sweden <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Discoveries:** Law of constant proportions <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Description: he discovered the law of constant proportions, which showed that inorganic substances are composed of different elements in constant proportions by weight. Based on this, in 1828 he compiled a table of relative atomic weights, where oxygen was set to 100, and which included all of the elements known at the time. Although this has now changed it is still an important contribution to atomic theories because it provides a well structured basis for the measurements of atomic weight. Without the law of constant proportions the periodic table would probably be a lot different compared to what we know today.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Jöns Jacob Berzelius **

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=**<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">3) 1800-1875 **= = =

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Birth:** November, 7, 1867 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Death:** July, 4, 1934 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Place of Birth:** Warsaw, Russia <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Discoveries: Marie Curry along with help from her husband Pierre were able to create the theory of radioactivity. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Description: Curie was the first woman to be awarded a Nobel Prize. Eight years later, she would receive the 1911 Nobel Prize in Chemistry, "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element. She won two nobel prizes in her lifetime, becoming the first person to ever do so. This was an astounding accomplishment especially for a women in this time period. Her contribution and works with radiation sadly led to her death, but paved the way for fellow scientists like Ernest Rutherford to continue and expand on her work.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Marie Curry **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Birth:** September, 22, 1791 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Death:** August ,25,1867 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Place of Birth**: South London, England <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Discoveries:** Invented system of oxidation numbers, invented the Bunsen burner. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Description: Faraday also discovered the laws of electrolysis and popularized terminology such as anode, cathode, electrode, and ion. Faraday worked extensively in the field of chemistry, discovering chemical substances such as benzene (which he called bicarburet of hydrogen), inventing the system of oxidation numbers, and liquefying gases such as chlorine. In 1820 Faraday reported on the first syntheses of compounds made from carbon and chlorine, C2Cl6 and C2Cl4, and published his results the following year. His contributions provided new theories and general ideas for the scientists of the future, this makes faraday a very important contributor to the development of the Atomic Theory.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Michael Faraday **

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Birth:** December, 15, 1852 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Death:** August, 25, 1908 <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Place of Birth:** Paris France <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">**Discoveries:** Discovered Radioactivity <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Description: Becquerel actually discovered radioactivity accidentally. He was performing another experiment when prior to the experiment he noticed something that led him to the discovery of radioactivity. Becquerel wrapped a fluorescent substance, potassium uranyl sulfate, in photographic plates and black material in preparation for an experiment requiring bright sunlight. However, prior to actually performing the experiment, Becquerel found that the photographic plates were fully exposed. This discovery led Becquerel to investigate the spontaneous emission of nuclear radiation. As a reward for his accomplishments he was awarded the nobel prize along with Marie Curry who also earned the prize for her work with radioactivity.
 * <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: 115%;">Henri Becquerel **

**__Wilhelm Rontgen__ Birth:** March 27, 1845, Paris. **Death:** February 10 1923
 * 4.) 1875-1900 **[[image:reich-chemistry/xray.jpg align="right"]]


 * Biography:** Rontgen had been a chemist since his college experience; he has had many publishing s usually involving specific heats and gases expansion. He one day while experimenting with crooks tube he thought about if there are beams of material being able to be emitted from with the tube possibly there are beams being emitted from out side the tube. This idea leads him to the discovery of the X-ray when he covered the tube with card board and held a piece of card board coated with barium platinocyanide he discovered that this plate glowed. He came to the conclusion that the Cathode ray being emitted by crooks tube had the ability to travel through some material and not travel through others. His theory was tested and proved by when his wife had put her hand on a plate covered in the barium platinocyaide and his theory was proved; the plate projected an image showing his wife’s skeletal hand and the wedding ring. This discovery also help him concluded that the beam can go through some objects for examples the less dense organic tissue. This discovers was showed to the world in 1895 and today Rontgen is considering the “father of radiology.”


 * [[image:reich-chemistry/moseley.jpg]] __Henry Moseley:__ Birth:** Nov 27, 1887, England. **Death:** August 10, 1915
 * Biography:** He developed Moseley’s law which is a justification of how atomic number and wave length share a systematic relationship. He proved that the atomic number is the number of “positive electrons” in an atom just not some number given to an element on the periodic table. He proved his the theory by using X-rays to diffracture certain elements and he saw a similar wave length that differed between elements.


 * [[image:reich-chemistry/Earnest_Rutherford.jpg]] __Ernest Rutherford:__ Birth:** August 30, 1871, New Zealand. **Death:** October 19, 1937.[[image:reich-chemistry/atom-bohr.gif width="340" height="228" align="right"]]


 * Biography:** Rutherford is most famous for experimenting with magnetism especially with high frequency oscillations involving iron. Rutherford in his early year had consistently experimented with radiation and created the terms (Alpha and Bata) which are terms used to describe different types or radiation (wave lengths.) Also Rutherford in his middle ages discovered more about radiation; things such as half-life and radioactive decay. He is most know for his creation of the Rutherford-Bohr model in which he and Neils Bohr created an accurate portrayal of what an atom looks like, Rutherford contributed with the existence of neutrons. In 1919 Rutherford became the first person to one element into another, (Nitrogen into Oxygen.) Overall he made many contributions to modern science.


 * 5.) 1900-1915 **


 * [[image:reich-chemistry/JJ_Thompson.jpg width="289" height="316"]] __J.J Thompson:__ Birth:** Decembe18 1856,Manchester. **Death:** August 30, 1940.


 * Biography:** His most famous discovery occurred while he was in America experimenting with cathode rays he discovered that the conduction of electricity in gases. In this experiment he was set up a tube with an electrical current running through it involving two cylinders with slits at the end of each tube. As he was doing the experiment he realized that there was a “negative” charge on one end not allowing the gases to slip out of the tube. He concluded that some of the particles in the gas were deflected by a “magnetic field like a negatively charged particle.” Over all he had discovered that electrons where present in atoms. Another big contribution to chemistry involving Thompson was that he was the first person to discover mass [|spectrometry], which were the early phases to discovering each element emits a certain particle of light.[[image:reich-chemistry/jj_thompsons.jpg align="right"]]

Thompson's theory of a "Plumb Pudding" model was not compeletly accurate and later throne out, but he was on the right track. He was correct on his idea that there was a negative charge particles within atoms as well as "Positively Charged" matter and electrons. But he was unable to prove there was and actual mass to these particles as well as the question why don't the particles just come together as we all no "opposites attract." Thompson also fail to identify the nucles and neutrons which are the core structure of every element.


 * [[image:reich-chemistry/r._millikan.jpg]]__Robert Millikan__: Birth:** March 22, 1868 Illinois. **Death:** December 19, 1953.


 * Biography:** As a young man he often was busy helping the family around there farm and spent a short time as a court reporter. He later attended Oberlin College in Ohio to receive his undergraduate degree in elementary physics. After Oberlin he work for a little to gain money to attend Columbian University, we he received a Masters in physics. Millikan is most famous for his discovery of those atoms or more specifically protons and electrons have charges as well as masses. His experiment involved the atomizing of oil droplets to be very small. He sprays the droplets into a chamber with a positive charge on one and a negative charge on the other. He also had only a tiny opening in a plate for the droplets to fall. Under the force of gravity and air resistance the droplets fell and to his surprise some of them were suspended. This led him to believe that some of the droplets must have had a negative charge for them to be suspended from the negative plate. He saw this through and eye glass he created in the side. He was able to calculate the mass of these tiny particles simply by **m · g** is which is exactly equal to the electric force applied q **· E**. Millikan was the first scientist to be able to prove this theory of electrons.


 * [[image:reich-chemistry/chadwick1.jpg width="162" height="227"]]__James Chadwick:__** **Birth:** October 20, 1891, England. **Death:** July 24, 1974.


 * Biography:** James Chadwick was a scientist and Professor who is known in the Chemistry world for his contributions involving nuclear chemistry. As a young man he attended Manchester University in 1905-1908 and graduated from the “Honors School of Physics.” He later became a professor there briefly. Chadwick’s experiment involving bombarding nitrogen molecules with alpha particles was one of the first experiments involving the disintegration of an atom. With this experiment he was able to prove the there is a “neutrally-charged” mass within an atom aka neutrons. Chadwick is also famous for being a part of the British hand in the “Manhattan Project” or building an atomic Bomb. He was one of a handful of scientist who urged the forces during the war how absolutely devastating the bombs would be is they were deployed.


 * 6.) 1915-1950 **
 * [[image:reich-chemistry/250px-180px-Werner_Heisenberg.jpg]]__Werner Heisenberg__ Birth:** December 5, 1901, Germany. **Death:** February 1, 1976.


 * Biography:** In Heisenberg’s early years he spent most of his time in different institutions of education in Germany for example the University of Munich. He quickly became very educated on all different ideas and principles of nuclear power and radiation and about atoms of course. In Germany 1933 Hitler took office and one thing he did was try to make Heisenberg the President of the University of Munich. This incident would later be known as the “Heisenberg Affair.” In 1939 He was recruited for the “Uranium club” to become one of ten scientists to work on atomic weapons for the Germans. In 1945 he was arrested for being associated with this research and was detain for one year in England. Heisenberg is most famous for his development of quantum mechanics and the general rules that he developed. This concept of similar patterns and equations would later become the core to the way atoms can be broken down and used for massive amounts of energy.


 * [[image:reich-chemistry/Erwin_Schrodinger.JPG width="323" height="277"]] __E__****__rwin Schrodinger__: Birth:** August 12, 1887, Austria. **Death:** January 4, 1961.


 * Biography:** Schrodinger was educated at the University of Vienna from 1906 to 1910 where he learned about physics specifically the eigenvalue problems which laid the foundation for his later success in the field of physics. He is most famous for the development of the “wave equation.” His theory was a description of how particles when broken down all emit different wave lengths. This theory is still completely untested but still has lead to many discoveries on how waves can travel as well as the specifity of certain types of waves can even lead to the breaking off of atoms.

**__Niels Bohr__: Birth:** October 7, 1885 Denmark. **Death:** November 18, 1967.


 * Biography:** Bohr as a young was educated in Physics and received his Ph. D in 1911. Bohr’s contribution to atomic history is of discovering that electrons orbit a nucleus as well as the number of electrons on the “exterior Orbit” can determine the chemical make up of that element. This property help confirm the theory that elements in the same group have very similar properties of reactivity as well as its physical properties. Bohr was very young when he proved his theory only 37. He laid the laws of how elements react is an involvement on electrons exchange. “If the atom absorbed energy, the electron jumped to a level further from the nucleus; if it radiated energy, it fell to a level closer to the nucleus. His model was a huge leap forward in making theory fit the experimental evidence that other physicists had found over the years.” These laws are still true today and are used by chemist to determine every combination of elements. Later in life he was involved in the “Manhattan Project” along Chadwick and Einstein. He like them was against the launching of the bomb because he like his colleagues understood the absolute devastation it could bring.

This is the modern day planetary model originally put together by Boar, and Rutherford. It is still used today by our modern scientists, however, it is revised to illustrate the detail and information we have learned in modern days. It is constucted with the nucleus consisting of protons and neutrons in the middle, and then outer rings consisting of electrons. The planetary model is still used as the main atomic model today.

=REFERENCES=


 * Democritus:[| http://en.wikipedia.org/wiki/Democritus] Picture: http://en.wikipedia.org/wiki/Democritus


 * Aristotle http://www.philosophypages.com/ph/aris.ht Pictures:[|http://www.philosophypages.com/ph/aris.htm>]http://tbn0.google.com/images?q=tbn:rxgyXRUzuCMxVM:http://www.kheper.net/topics/cosmology/4elements.gif

[|http://www.btinternet.com/~glynhughes/squashed/epicurus.jpg&imgrefurl=http://www.btinternet.com/~glynhughes/squlla:en-US:official%26sa%3DN]]]
 * Epicurus: http://www.epicurus.net/ Picture:
 * John Dalton: http://en.wikipedia.org/wiki/John_Dalton Picture: http://en.wikipedia.org/wiki/John_Dalton


 * Antoine Lavouser: http://scienceworld.wolfram.com/biography/Lavoisier.html Picture: [|Antoine.]

Picture: http://www.chemheritage.org/classroom/chemach/electrochem/berzelius.html
 * Jons Jacob Berzelius:http://www.chemheritage.org/classroom/chemach/electrochem/berzelius.html


 * Marie Curry: http://en.wikipedia.org/wiki/Marie_Curie Picture:http://en.wikipedia.org/wiki/Marie_Curie

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