Rutherford introduced the concept of the nucleus that is present in the center of the atom, using his scattering experiment.
The nucleus consists of protons and neutrons that contribute to the mass of the atom.
Rutherford proposed that the electrons revolve in their orbits around the nucleus much like the planets revolving around the sun in their respective orbits.
The electrostatic attractive force of the nucleus on the electrons supplies the necessary centripetal force for their orbital rotation.
But, according to the electromagnetic theory of light, an accelerated or decelerated electrically charged particle emits electromagnetic radiation and thereby loses its energy so that its velocity is decreased.
Since the electron revolving in its orbit is acted upon by the centripetal force its motion is accelerated.
Thus, it will lose energy by the emission of electromagnetic radiation.
So due to the attractive force of the nucleus, it will move in orbits of continually decreasing radii and its path will be a spiral.
Finally, it will fall upon the nucleus itself and disappear.
In order to remove this drawback, Neils Bohr put forward Bohr's postulates based on the quantum ideas proposed by Planck.
