1875---1900

=****Wilhelm Conrad Röntgen** **=  []  Date of Death- F ebruary 10, 1923 Place of Origin- Lennep, Germany. Year of Discovery-1895 **
 * Date of Birth- March 27, 1845

Wilhelm Conrad Röntgen didn’t start out as the scientist we all know of today, but began life as the son of a cloth merchant. While living in the Netherlands, Röntgen showed no specific signs of scientific propensity, but instead had an ability to create marvelous mechanical gadgets. When he was 18, he attended a technical school until he was expelled for offense he did no commit. After some time though, he moved on and received a Ph.D. at the Polytechnic at Zurich and began to work as an assistant for scientist named Kundt. For several years he worked for him until Röntgen found his way up the scientific success ladder and found himself as the Chair of Physics in the University of Giessen.

“On the evening of November 8, 1895, he found that, if the discharge tube is enclosed in a sealed, thick black carton to exclude all light, and if he worked in a dark room, a paper plate covered on one side with barium platinocyanide placed in the path of the rays became fluorescent even when it was as far as two metres from the discharge tube” (nobelprize.org). As Röntgen placed different objects in the path of the rays, they would show up on a piece of photographic paper only more transparent. Then, he placed the hand of his wife in the path of the rays and created the world’s first human x-ray.

**Henri Becquerel** []  Date of Death- August 25, 1908** Year of Discovery- 1896**
 * Date of Birth- December 15, 1852
 * Place of Origin- Paris, France.

Being the son and the grandson of two very renowned men of science and scholars, Henri Becquerel was born to do great things. In 1888 he received a degree of “docteur-ès-sciences” from Polytechnic and took over his father’s position as the Chair of Applied Physics at the Conservatoire des Arts et Metiers. Soon after that, he was appointed Professor of Applied Physics in the Department of Natural History at the Paris Museum and became a Professor at the Polytechnic in 1895 (nobelprize.org).

Henri Becquerel worked mostly with polarization of light, absorption of light crystals, and terrestrial magnetism, his atomic achievement came from uranium salts. After the discovery of x-rays, Becquerel became interested and wondered whether the phosphorescence of natural materials and the x-rays were the same type of reaction. However, Becquerel definitely became an example of the phrase “most discoveries are just lucky accidents.” What happened was he left some samples of uranium salts on top of a piece of photographic paper and placed it in his sock drwer for safe keeping while he left for several days. Then when he came back and checked on the salts, they left marks upon the papers. “The phenomenon was found to be common to all the uranium salts studied and was concluded to be a property of the uranium atom” (nobelprize.org).

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=**J.J. Thomson **=  [] **Date of Birth- December 18, 1856 Date of Death- August 30, 1940 Place of Origin- Manchester, England. Year of Discovery- 1897**

J.J. Thomson’s successes started early, as he was already enrolled at Owens College, when he was only 14 years old. Six years later, he put his name down for Trinity College in where he later became a Fellow of Trinity in 1880. Before his primary discovery, he had a renowned interest in the atomic structure. He even wrote several papers on the subject, mainly His //Application of Dynamics to Physics and Chemistry,// //Notes on Recent Researches in Electricity and Magnetism,// and his Adams Prize winning //Treatise on the Motion of Vortex Rings//. He even went as far as to go to America deliver four lectures all of which were later known published as //Discharge of Electricity through Gases//.

In 1897, J.J Thomson performed several experiment consisting of electricity and a cathode ray tube. This tube is a “glass vacuum tube into which an electron gun emits a flow of electrons guided by an electrical field towards a screen covered in small phosphorescent elements.” J.J Thomson was confused with this neon like lights, just like all scientist of his time. The question amongst them were whether the beams of light were actual light waves or solid mater. However with more experiment, he concluded that these mysterious rays are streams of particles much smaller than atoms, they are in fact minuscule pieces of atoms, AKA, the electron. (ALIA) 


 * //The Plum Pudding Model...//**

J.J. Thompson formed the plum pudding model of an atom which attempted to explain why an atom’s charge was electrically neutral. The plum pudding model of an atom was formed in a way that could be easily described to people outside of the scientific world in a very basic and common manner. The pudding in the model represents a positive charge and takes up the majority of the atom. The plums with in the pudding are described as having a negative charge and together with the positive pudding, the electron is therefore neutral.

Today, the model of an atom contrasts in many ways, but the importance of Thompson’s model is that he tried to explain the neutrality of atoms. In theory his idea of negative particles and positive particles causing a neural charge is accurate but the way in which it actually appears in an atom is a lot different. In Thompson’s model, the positive charge was encompassing the entire atom, but today we know that the positive charge is only found with in the nucleus in the center of the atom. The model was soon disprooved as accurate when Rutherford's gold foil experiment showed that some positive particles deflected. The only way that this could be explained was to assume that the positive particles were not "pudding-like" and were focused in the center of the atom.



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