CHEM 1211 Lecture Notes - Cathode Ray Tube, Cathode Ray, William Crookes
4 Feb 2014
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Law of multiple proportion: if two elements (a &b) can form two compounds, the different masses with which they combine may be expressed as a ratio of small whole numbers. Sir william crookes invented a vacuum tube to study atomic structure. A ray emanated from the negative electrode (cathode) J. j. thomson: first deflected a beam of cathode rays by applying an electric field of known strength (crt experiment) Varied a magnetic field perpendicular to the electric field. Determined charge to mass ratio (3/m) of an electron. Conceives a new model of the atom: plum-pudding model. Atoms consist of a solid bulk of positive charge with electrons dispersed throughout. Couloumb"s law: oppositely charged particles will be attracted to one another and charges of same sign will repel. F = (k * q1 * q1) / d^2. Fired x-rays into a chamber which caused electrons to be removed from the molecules in the air.
