1. Major portion of the atom is empty.
2. The whole mass of the atom is concentrated in the center of atom called nucleus.
3. The positively charged particles are present in the nucleus of atom.
4. The charge on the nucleus of an atom is equal to (+z.e) where Z= charge number, e = charge of proton.
5. The electrons revolve around the nucleus in different circular orbits.
6. Size of nucleus is very small as compare to the size of atom.