Book Title: Microcosmology Atom in Jain Philosophy and Modern Science
Author(s): Jethalal S Zaveri, Mahendramuni
Publisher: Jain Vishva Bharati
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Atom in Modern Science
the "basic building blocks" - the ultimate units of matter? Can we subdivide them still further into smaller and simple particles? Would it be possible to reduce all different atoms to perhaps a few really simple particles?
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In the middle of the last century, William Prout, an English chemist put forth a hypothesis that the atoms of all elements are made up of various numbers of hydrogen atoms. This hypothesis was based on the fact that the atomic weight of various elements were in most cases very nearly exact multiples of that of hydrogen. Thus atoms of oxygen which are sixteen times heavier than those of hydrogen, must be composed of 16 hydrogen atoms, somehow stuck together. But the facts found at that time were unfavourable to the acceptance of this bold hypothesis. Isotopes were not discovered and the chemical atomic weight of chlorine for instance, being 35.5 was in direct contradiction to Prout's hypothesis. He died without ever learning how right he actually
was.
In 1919, British Physicist F.W. Aston discovered that ordinary chlorine was actually a mixture of two different kinds of chlorine possessing identical chemical properties but having different atomic weights: 35 & 37. Further study revealed the striking fact that a mixture of several components, identical in chemical properties but differing in atomic weights, made up most of the elements. They were called isotopes. Prout's forgotten hypothesis was given a new life and was reformulated by saying that nuclei of various atoms are composed of various number of hydrogen nuclei called protons.
An important step towards a better understanding of nuclear structure of atom was the discovery of neutron as the second constituent of nucleus. It is a particle which has roughly the same mass as proton, but does not carry an electric charge. Actually the nuclei of various elements are composed of protons as well as neutrons. The existence of neutrons was suggested by Rutherford in 1920, but they were found experimentally only in 1932.
