For the following questions answer them individually
Among $$[Ni (CO)_4], [NiCl_4]^{2-}, [Co(NH_3)_4Cl_2]Cl, Na_3[CoF_6], Na_2O_2$$ and $$CsO_2$$, the total numberof paramagnetic compounds is
A plot of the number of neutrons (NV) against the number of protons (P) of stable nuclei exhibits upward deviation from linearity for atomic number, Z > 20. For an unstable nucleus having N/P ratio less than 1, the possible mode(s) of decay is(are)
The reagent(s) that can selectively precipitate $$S^{2-}$$ from a mixture of $$S^{2-}$$ and $$SO_{4}^{2-}$$ in aqueous solution is(are)