Thompson won the Nobel Prize in physics for establishing the existence of electrons. Thomson thus concluded that atoms are divisible and that the corpuscles are their building blocks. It was evident that electrons are a component of all neutral atoms, the counterbalancing positive charge being carried by one or more of their other constituent parts. Thomson originally called these particles “ corpuscles.” The Irish physicist George Johnstone Stoney proposed the name electron for these particles. For example, by the action of ultra-violet light on metals, by heating metal wires, or by the ionizing action of X-rays. He showed that these charged particles could be obtained from just about any material. He calculated he must have bodies much smaller than atoms and a very large value for their charge-to-mass ratio. Thomson showed that cathode rays were composed of previously unknown negatively charged particles. Eventually, experimentation into electricity and radioactivity indicated that particles of matter smaller than the atom did exist. All of the results of chemical experiments during this time indicated that the atom was indivisible. This fact explains the overall neutral charge of the atom.įor almost 100 years (from Dalton’s A New System of Chemical Philosophy), atoms were thought to be the smallest possible division of matter. According to the plum pudding model, an atom consists of a sphere of positive matter within which electrostatic forces determine the positioning of the negatively charged corpuscles. Thomson in 1904 and is known as the Plum pudding model or the Thomson model of the atom. The original model of an atom, based on the discovery of the electron, was proposed by J.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |