A simple density functional approach is proposed, within the framework of spin-polarized Kohn-Sham theory, for the calculation of chemical hardness, dipole as well as quadrupole polarizability and covalent radius of atomic systems. An important novel feature of this approach is that the spin-orbitals from only a single Kohn-Sham calculation for the neutral atom are utilized for predicting all these properties which also include the radii of the corresponding positive and negative ions. The prescriptions are simple, involving well-defined approximations, and the calculated results show good agreement with available standard results.