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WELCOME TO ATOMIC STRUCTURE. INTRODUCTION.
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WELCOME TO ATOMIC STRUCTURE
INTRODUCTION • This is the story of how materials are made up from atoms. There are only about 100 kinds of atoms in all the Universe, and whether these atoms form trees or tyres, ashes or animals, water or the air we breath, depends on how they are put together. The same atoms are used again and again. Structure determines not only the appearance of materials, but also their properties.
ELETRICAL NATURE OF MATTER • A GLASS ROD ON RUBBING WITH SILK ACQUIRES POSITIVE CHARGE. SIMILARLY AND EBONITE ROD ON RUBBING WITH FUR ACQUIRES NEGATIVE CHARGE. MANY METALS AND SOLUTION ARE CONDUCTORS. ALL THESE INDICATE THAT MATTER IS ELETRICAL IN NATURE.
PRODUCTION OF CATHODE RAYS
PRODUCTION OF CATHODE RAYS • An important source of X rays is synchrotron radiation. X rays are also produced in a highly evacuated glass bulb,called an X-ray tube, that contains essentially two electrodes—an anode made of platinum, tungsten, or another heavy metal of high melting point, and a cathode. When a high voltage is applied between the electrodes, streams of electrons (cathode rays) are accelerated from the cathode to the anode and produce X rays as they strike the anode
Rutheford made a theoretical analysis of angles of scattering in accordance with Thomson's theory of atom and in accordance with his own theory. He assumed that atom consisted of positive charged nucleus and negative charged electrons circling around the nucleus. Then his theoretic calculations he compared with the experiment result. Alpha particles going through atom created in accordance with the "plum cake" model wouldn't be strong abberated because the electric field in that atom wouldn't be strong. In the model created by Rutheford the field is much stronger near to the nucleus, so some of alpha particles are much more abberated. The other going in the far distance to the nucleus are almost not at all abberated. The probability that any alpha particle will hit the nucleus is small but there is such a chance.
THANKYOU BY M. MOTCHA MARY, FROM T.V. NAGAR HIGH SCHOOL, AMBATTUR, CHENNAI - 53