Tuesday, April 20, 2021
Atomic Structure
In ancient times, the philosophers were of the opinion that every substance is made up of small particles, but they had no experimental evidence to confirm that in 1873 Dalton proposed the atomic theory, according to this theory, every substance According to Dalton, atoms cannot be divided by any physical or chemical method.
In 1897, Sir JJ Tamson discovered electrons and around the same time Bacural discovered radio activation. Then it was proved by experiments that atoms of each element are negatively charged particles electrons, but because atoms are neutral, they must have the same amount of positive charge, in addition to that the mass of electrons is very small compared to atomic mass, so atoms The mass of it must be in the positive charge present in it, the size of the atom can be estimated by many methods and it is 10. At that time there was no knowledge regarding the distribution of electron, positive charge and mass within the atom.