422-004+J.Farian+Big+Timeline+Project

=**__History of an Atom__**= = = =media type="file" key="NJMD.mp3" width="51" height="51"= = =

__Overview of Scientists__
1. Democritus= 460-370 B.C. Greek 2. Aristotle= 384-322 B.C. Greek 3. John Dalton=1766-1844 English 4. Wilhelm Conrad Röntgen= 1845-1923 German 5. Henri Becquerel= 1852-1908 French 6. J.J. Thompson= 1856-1940 English 7. Marie Curie= 1867-1934 Polish 8. Robert Millikan= 1868-1940 American 9. Ernest Rutherford= 1871-1937 Dutch 10. Niehls Bohr= 1885-1962 Danish 11. James Chadwick= 1891-1974 English 12. Werner Heisenberg= 1901-1976 German 13. Hans Geiger= 1882- 1945 German 14. Ernest Marsden= 1889 - 1970 British-New Zealand 15. Erwin Shrodinger= 1887-1961 Italian

__**Democritus**__
Date of Birth: 460 B.C Date of Death: 370 B.C. Country of Origin: Abdera, Thrace Year of Discovery: Late 5th century Contribution: The first to discover that every object is made up of arrangements of things he later named atoms or atom(Greek meaning "indivisible"). Before Democritus no one had even thought of anything like the atom, about 150 years before Democritus many people thought that all objects were made of four elements. These elements were earth, wind, water and fire.

__**Aristotle**__
Date of Birth: 384 B.C. Date of Death: 322 B.C. Country of origin: Stageira, Chalcidice Year of Discovery: Unknown Contribution: Determined that there were 5 main elements (Fire, Earth, Air, Wind. Aether). Also he found that there are two types of motion, natural and violent motions.

Date of Birth: September 6, 1766 Date of Death: July 27, 1844 Country of Origin: Eaglesfield, Cumbria Contribution: Atomic theory which states that an element is pure because all of the atoms are identical. Dalton also came up with the Law of Simple Multiple Proportions which is [[image:file:moz-s[[image:Neils_Bohr.JPG]] [[image:Dalton_Art_1.JPG width="332" height="342" caption="Dalton_Art_1.JPG"]]
 * __John Dalton__**

__**Wilhelm Conrad Röntgen[[image:roentgen.gif align="right" caption="Wilhelm Conrad Rontgen"]]**__
Date of Birth: March 27, 1845 Date of Death: February 10, 1923 Country of origin: Lennep, Germany Contribution: In 1895 he found that, if Crooks Tube covered with a thick black carton to exclude all light, and if he worked in a dark room with a paper plate covered on one side with barium platinocyanide that was placed in the path of the rays became fluorescent even when it was as far as two meters from Crooks Tube. During subsequent experiments he found that objects of different thicknesses interposed in the path of the rays showed variable transparency to them when recorded on a photographic plate. When he immobilised for some moments the hand of his wife in the path of the rays over a photographic plate, he observed after development of the plate an image of his wife's hand which showed the shadows thrown by the bones of her hand and that of a ring she was wearing, surrounded by the penumbra of the flesh, which was more permeable to the rays and therefore threw a fainter shadow. In further experiments, Röntgen showed that the new rays are produced by the impact of cathode rays on a material object. Because their nature was then unknown, he gave them the name X-rays.

**__Henri Becquerel__**
Date of Birth:1852 Date of Death:1908 Country of origin: French Contribution: He realized that when you took uranium salt and put them near photographic plate they would ionize the gases. He also discovered spontaneous radioactivity.

[[image:thomson.jpg align="right" caption="J.J. Thomson"]]
Date of Birth: December 18, 1856 Date of Death: August 30, 1940 Country of origin: Cheetham Hill, Manchester Contribution: Thomson used cathode ray tubes in 3 different experiments and discovered an important part of the atom, the electron. Through each experiment he came closer and closer to finding out that atoms are both positively and negatively charged that combine and neutralize the atoms charge. He also dicovered the isotope. Thomson channeled a stream of ionized neon through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path. Thomson observed two patches of light on the photographic plate (see image on the left), which suggested two different parabolas of deflection. Thomson concluded that the neon gas was composed of atoms of two different atomic masses (neon-20 and neon-22).



**__Marie Curie__**
Date of Birth: November 7, 1867 Date of Death: July 4, 1934 Country of origin: Warsaw, Poland Contribution: Marie Curie was one of the few female scientists of her time and she broke the barrier for women to get accepted into the science world. She discovered two new elements, polonium and radium. She did this by isolating these elements from a mixture called pitch blend. She developed efficient ways to separate the elements. She is the only person to win the Nobel Prize in two different sciences. Hlaf of one in physics with Henri Becquerel with work on spontaneous radioactivity and one in chemistry for her discovery of two elements.



**__Robert Millikan__**
Date of Birth: March 22, 1868 Date of Death: December 19, 1953 Country of origin: USA Contribution: Millikan's "flling-drop method" allowed him to determine the charge carried by electrons. He then, in 1910, proved that the experiment was correct for all electrons, thus demostrating the atomic structure of electricity. He later proved his law of whne things fall to the ground after entering the Earth's atmosphere. In the early 20s he worked mostly on ultraviolet and X-rays. Actually pulling down the ultraviolet spectrum to a place where no one else had taken it before. All these accomplishents won him the Nobel Prize in Physics in 1923.



**__Ernest Rutherford__**
Date of Birth: August 30, 1871 Date of Death: October 19, 1937 Country of origin: Nelson, New Zealand Contribution: In 1898 he reported the discovery of alpha and beta rays in uranium radiation. While at Cambridge he worked on a detector of electromagnetic waves. He worked with his Professor Thomson who saw the brilliance Rutherford had. Together they were able to observe the ions in the gases that had been treated with X-rays. Rutherford later made a model of the atom which part the nucleus to the world. He would then go on to work with Bohr and Chadwick who by themselves were great scientists.



**__Niels Bohr__**
Date of Birth: October 7, 1885 Date of Death: November 18, 1962 Country of origin: Copenhagen, Denmark Contribution: Bohr worked under JJ Thomson and Rutherford while he was at Cambridge and there he was able to make some great discoveries. He was able to crack the readioactive phenomena. His best work though was off of Rutherford's atom model. Bohr was able to create a more indepth model that is still used today to observe chemical and physical properties of different elements in the world.

__**James Chadwick**__
Date of Birth: October 20, 1891 Date of Death: July 24, 1974 Country of origin: Cheshire, England Contribution: Chadwick, with the help of Rutherford, was able to complete the transmutation of light elements bu bombarding them with alpha particles. That lead to many studies of the atmoic structure and nuclei. In the 1927 he was elected Fellow of the Royal Society, only 4 years after he became Assistant Director of Research in the Cavendish Laboratory. But Chadwick's biggest discovery by far was that of the neutrons. This was the first time anyone had said that there was a particle that didn't have any electrical charge in it. A total opposite of the alpha particles everyone was using. Chadwick was knighted in 1945.

__**Werner Heisenberg**__
Date of Birth: December 5, 1901 Date of Death: Feburay 1, 1976 Country of origin: Wurzburg, Germany Contribution: After being taken by USA troops to England Werner returned home to Germany to study more. In 1925, when he was only 23 years of age, his name will be put with quantum machines and the theory behind it. He is most known for his contradiction of Neils Bohr's electrons work. He said that since we have no way of knowing the orbit of the electrons we cannot know that they have a position in space. This lead to his theory on matrices and matrix equations

__** Date of Birth: September 30, 1882 Date of Death: September 24, 1945 Country of Origin: Neustadt-an-der-Haardt, Germany Contribution: Hans worked with Rutherford in the chemistry field and Hans' law named after himself helped to later create Rutherford's atomic model. In Germany he worked with many scientist and in 1907 went to the University of Manchester to continue his work after he recived his doctorate in 1906. He would go onto betray his Jewish colleagues because of his devotion to the Nazi party.
 * __Hans Geiger


 * __Ernest Marsden[[image:http://tbn0.google.com/images?q=tbn:0nKz-mC9HxQdIM:http://dbhs.wvusd.k12.ca.us/webdocs/Gallery/Marsden-1.GIF width="191" height="183" align="right" link="http://images.google.com/imgres?imgurl=http://dbhs.wvusd.k12.ca.us/webdocs/Gallery/Marsden-1.GIF&imgrefurl=http://dbhs.wvusd.k12.ca.us/webdocs/Gallery/Gallery0.html&h=284&w=217&sz=17&hl=en&start=3&um=1&tbnid=0nKz-mC9HxQdIM:&tbnh=114&tbnw=87&prev=/images%3Fq%3Dernest%2Bmarsden%2B%26svnum%3D30%26um%3D1%26hl%3Den%26safe%3Doff%26rls%3DGWYA,GWYA:2005-19,GWYA:en"]]__**

Date of Birth: February 19, 1889 Date of Death: February 19, 1970 Country of Origin: Lancashire, NZ Contribution: He and Hans Gieger were the two scientist who created the great Gieger-Marsden experiment or the gold foil experiment. In this experiment the two men shot marbles at other marble to try and determine how the electron and proton inside the atom collide with on another. He then was put into the army for France and recieved the Military Cross as a Royal Engineer. Marsden's career recognitions included fellowship in the Royal Society of London in 1946, president of the Royal Society of New Zealand in 1947, and knighthood in 1958.


 * __Erwin Shrodinger[[image:http://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Erwin_Schr%C3%B6dinger.jpg/200px-Erwin_Schr%C3%B6dinger.jpg width="176" height="195" align="right" link="http://en.wikipedia.org/wiki/Image:Erwin_Schr%C3%B6dinger.jpg"]]__**

Date of Birth: August 12, 1887 Date Of Death: January 4, 1961 Country of Origin: Vienna, Italy Contribution: Once he made his move to Berlin, which was becoming the center for scientist, he start to get noticed. HIs best known work are of his papers in which he talks about unifying gravity and electromagnitism. His book "What is Life?" is still a popular book today for chemist of all ages.

**__Models Of Atoms

1) Date Discovered: unknown__**
 * __Description:__** This is a very basic model where the atom is just a small round ball. This was developed in Ancient Greece by many great thinkers.

Description:__** This model was created by Neils Bohr and it shows how the elctrons in an atom float around the nucleus. This model will later be improved ny Rutherford's model. But this model is still accepted in some science labs as the model of an atom. This is called the Electron Cloud model.
 * __2) Date Discovered: 1920[[image:http://www.windows.ucar.edu/cool_stuff/images/electron_cloud_sm.jpg width="163" height="166" align="right"]]

Description:__** This is the model developed by J.J. Thomson. He thought that the atom was a charged particle that had a positive inside with a negative outside. He said that the outside was a cloud of electrons that a negative particles and the inside was protons that were positive particles. This is called the Plum Pudding Model.
 * __3) Date Discovered:1904[[image:http://upload.wikimedia.org/wikipedia/commons/thumb/f/ff/Plum_pudding_atom.svg/348px-Plum_pudding_atom.svg.png width="167" height="142" align="right" caption="Image:Plum pudding atom.svg" link="http://upload.wikimedia.org/wikipedia/commons/f/ff/Plum_pudding_atom.svg"]]


 * __4)[[image:http://worsleyschool.net/science/files/rutherford/atom.gif width="150" height="143" align="right"]]Date Discovered:__** Late 19th century
 * __Description:__** This is the model that Rutherford put out into the chemistry world. He said that the atoms were covered with a cloud of electrons and in the center was the nucleus and that was where the alpha particels were. Neils Bohr's model was the simple verison of this, then Rutherford improved upon it. This is known as the Rutherford-Bohr Model.

__**5) Date Discovered: 1915 Description:**__ This is the model of the atom that is used today and this model is the most in depth about how the atom actually looks. It shows the orbit of the electrons around the atom and it has the neutrons and protons in the middle of the nucleus. This is called the Planetary Model.

1)Ancient Eygpt flourishes on the Nile Valley, first to use the proccess of mummification.(3000 B.C.) 2)Twelve Tables of Roman law(431 B.C.) 3)1. Punic War(264-241 B.C.) 1)Ottoman Empire and Egypt have a war.(1832) 2)Quebec founded (1608) 3)Scotland becomes independent (1328)
 * __World Events__**
 * Ancient:**
 * 500-1875:**

1)1882 AD Triple Alliance between Germany, Austria-Hungary and Italy 2)1886 AD the general strike in the United States for eight-hour workday 3)1900 AD First zeppelin flight on Lake Constance, Germany
 * 1875-1900:**


 * 1900-1915:**

1)1901 AD The Nobel Prizes were first awarded 2)1903 AD Assassination of Serbian King Alexander Obrenovic and Queen Draga 3)1912 AD Titanic sunk = =


 * 1915-1930:**

1)1918 AD Woodrow Wilson's Fourteen Points 2)1924 AD Vladimir Lenin died 3)1929 AD the Lateran Treaty between Italy and the Vatican: creation of the State of the Vatican City


 * 1930-1945:**

1)1931 AD the Japanese invasion of Manchuria 2)1933 AD Dachau, the first Nazi concentration camp, was opened 3)1939 AD Nazi Germany attacks Poland on September 1, beginning of Second World War


 * 1945-Present:**

1)1968 AD Martin Luther King, Jr. was assassinated on April 4 2)1981 AD Pope John Paul II. was shot in Vatican on May 13 3)1998 AD Bill Clinton admitted he had an inappropriate relationship with Monica Lewinsky on August 17

__**Biliography**__

http://en.wikipedia.org/wiki/Erwin_Schr%C3%B6dinger [|www.Google.com] http://en.wikipedia.org/wiki/Hans_Geiger http://www.historyexplorer.net/?World_History_Timeline:1996_AD_-_2000_AD http://www.historyexplorer.net/?World_History_Timeline:1981_AD_-_1989_AD http://www.pbs.org/wgbh/aso/databank/entries/dp13at.html http://www.historyexplorer.net/?World_History_Timeline:1876_AD_-_1900_AD [| www.nobelprize.org]