Differences between neutron and proton distributions were investigated
for beta-stable nuclei and for chains of isotopes and isotones up to
drip line nuclei. The relativistic mean field theory with the paramete
r set NL-3 was used in calculations. Dependence of neutron and proton
radius and mean density on relative neutron excess I = (N - Z)/A was f
ound. Different deformations of neutron and proton matter were noticed
.