Discovery of electron J.J. Thomson measured e/m of a “tiny negatively charged particle”, 1897 R. Millikan measured e, 1910 and Planck’s constant in 1912-1915 The first discovered particle! – quite elementary until today Structure? The major experimental facts: 1. the periodic table of elements – Dmitri Mendeleev, 1869 2. the stable matter is electrically neutral Major hypothesis (J.J. Thomson): Positively charged spheres orbited by electrons – from the side raisin pudding positively charged stuff (pudding) stuffed with electrons – raisin Joseph John Thomson (1856-1940) Robert Andrews Millikan (1868-1953)
Posted on: Thu, 06 Feb 2014 07:32:35 +0000