The Atom :: essays research papers fc

The Atom     In the spring of 1897 J.J. Thomson demonstrated that the beam of glowing topic in a cathode-ray tube was not made of light waves, as "the almostunanimous opinion of German physicists" held. Rather, cathode rays werenegatively charged particles boiling discharge the negative cathode and attracted tothe positive anode. These particles could be deflected by an electric field andbent into curved paths by a magnetic field. They were much lighter thanhydrogen atoms and were undistinguishable "what ever the gas through which the dischargepasses" if gas was introduced into the tube. Since they were lighter than thelightest known kind of matter and identical regardless of the kind of matterthey were born from, it followed that they essential be some basic constituent partof matter, and if they were a part, then there must be a whole. The real, natural electron implied a real, physical atom the particulate theory ofmatter was therefore justif ied for the first time convincingly by physicalexperiment. They sang success at the one-year Cavendish dinner.     Armed with the electron, and knowing from other experiment that what wasleft when electrons were stripped away from an atom was much more massiveremainder that was positively charged, Thomson went on in the next decade todevelop a model of the atom that came to be called the "plum pudding" model.The Thomson atom, "a number of negatively electrified corpuscles enclosed in asphere of uniform positive electrification" like raisins in a pudding, was ahybrid particulate electrons and diffuse remainder. It served the usefulpurpose of demonstrating mathematically that electrons could be position in astable configurations within an atom and that the mathematically stablearrangements could account for the similarities and regularities among chemicelements that the periodic table of the elements displays. It was becomingclear that the electr ons were responsible for chemical affinities betweenelements, that chemistry was ultimately electrical.     Thomson just missed discovering X rays in 1884. He was not so unluckyin legend as the Oxford physicist Frederick Smith, who make up that photographicplates kept near a cathode-ray tube were liable to be fogged and merely told hisassistant to move them to another place. Thomson noticed that glass subway held"at a distance of some feet from the discharge-tube" fluoresced just as the wallof the tube itself did when bombarded with cathode rays, but he was too intenton studying the rays themselves to dish the cause. Rontgen isolated the effectby covering his cathode-ray tube with black paper. When a nearby screen offlorescent material still glowed he realized that whatever was cause the