Jethalal S. Zaveri
Prof. Muni Mahendra Kumar
For fully understanding the structure of matter, we have to descend from the macroscopic to the microscopic level. This has to be done in two stages - first, at the atomic level and second, at the subatomic level.
The first real step forward in an understanding of the structure and the various chemical and physical properties of matter was taken when it was accepted that atoms were not simple indivisible particles of various shapes and sizes, but on the contrary rather complex mechanisms with a number of independent parts in motion.
At the turn of the century, inexplicable phenomena connected with the structure of atom were discovered. Discovery of a new radiation - X-ray - gave the first indication that the atom had some structure. Radioactivity gave definite proof of the complex nature of atom, when it was discovered that radioactive substances not only emit radiations but also transform themselves into atoms of new substance.
