Atomic Structure, Radiochemistry and Chemical Bonding

Abstract

In previous chapters we have seen how Dalton’s atomic theory encountered difficulties, especially during the first half of the nineteenth century. After 1860 the chemical atom became so useful, especially to organic chemists, that only a few dissenting voices were heard in this branch of the science. However, to many physicists the atomic concept seemed unnecessary, and some of the great advances in nineteenth century physics had been made without reference to atomism. Then, in a series of discoveries which were made in rapid succession around the turn of the century, the existence of atoms was established to the satisfaction of everyone. All atoms were shown to contain identical subatomic particles, which were called electrons. Furthermore, certain atoms were shown to be undergoing spontaneous and continuous transmutation into others. The atomic concept may have been vindicated, but at the cost of disproving Dalton’s tenets of the indivisibility and immutability of atoms. Further advances placed the periodic table on a firm theoretical basis, and provided an explanation of the forces involved in chemical bonding.