Abstract
We have studied the present theoretical understanding of size of neutron, proton, matter, and charge distributions in spherical nuclei. The ground-state nuclear radii have been evaluated in the framework of the relativistic mean-field approach within the Hartree approximation. A comparison has been done with the radii obtained with the nonrelativistic density-dependent Skyrme interactions. It is pointed out that with an increase in isospin of nuclei, the neutron rms radii in the relativistic mean-field approach are larger than both the empirical data and the predictions of the Skyrme mean field.