  In the present work we report comprehensive set of shell model calculations
for arsenic isotopes. We performed shell model calculations with two recent
effective interactions JUN45 and jj44b. The overall results for the energy
levels and magnetic moments are in rather good agreement with the available
experimental data. We have also reported competition of proton- and
neutron-pair breakings analysis to identify which nucleon pairs are broken to
obtain the total angular momentum of the calculated states. Further theoretical
development is needed by enlarging model space by including $\pi 0f_{7/2}$ and
$\nu 1d_{5/2}$ orbitals.
