The concept of atom was put forward by Greek philosopher Democritus who believed that all matter is made of multiple small indivisible particles called the “atom”.
Later, chemist John Dalton further explained how every element is made up of indivisible atomic particles and put forward his atomic theory to better describe the atom. Although his theory set the base for exploration of atom it did have its own limitations. It was later discovered that the atom was in-fact divisible into smaller particles namely - proton, electron and neutron which exist in particular regions of the atom and held a fixed charge and mass.
These discoveries happened over time and were done by multiple scientists namely Crooks, Thomson, Goldstein and Chadwick. Further developments on the atomic model were carried out by Lord Rutherford followed by Neil Bohr.
