ATOMIC STRUCTURE:-

It deals with the important particles of atom and arrangement of these atoms in atomic structure. John Dalton in 1808, proposed that matter is made up of extremely small particles and invisible particles called atom (Greek atom means these atoms cannot be cut). John Dalton in 1808 put forward the first theory about the structure of matter which is known as Dalton’s atomic theory. It state that “all mater is composed of extremely small particles called atoms which are regarded to be invisible and spherical particles. “ This theory remained undisputed up to the 19^th century. But, the theory was discarded when the further researchers provide that atom consists of still smaller particles like electron, proton and neutrons.                         

                                   By many scientists like J.J.Thomson, Goldstein, Rutherford, Chadwick the research was done and find that the atom is not smallest particles and invisible particles but it has complex structure of its atom. Atom was made up of smallest particles like electron, proton and neutron and present about 35 sub-atomic particles.