Atoms and elements are the basic back bone of the universe. explain what this statement means and how the idea of the atom has changed over time ( ! )

The above statement states that the atom and the elements, which is made up of the atom itself, is the most important and fundamental to define the universe, Every object or matter in the space has fundamental to it and that is atom. The model of atom has far changed from Dalton's plum pudding model in which he assumes the positive core and the negative part of the atom is randomly present just like plum in plum pudding cake, then Rutherford's model which was far promising than Dalton's. assuming electron in spatial orbit revolving around the nucleus. Then Niels Bohr model and it's postulates he explains the electron energy transition between orbits and lined spectrum of hydrogen atom, also says that electron till stays in the stationary orbit with integral multiple of h/2π never loses its energy .. it loses when it jumps from higher energy state orbit to lower one .. in the form of radiation mostly a Photon