The number of resonance structure for N is _________.

The number of lone pairs of electrons in N₂O₃ is ___________.

For the octahedral complexes of Fe³⁺ in SCN^$$-$$ (thiocyana-to-S) and in CN^$$-$$ ligand environments, the difference between the spin-only magnetic moments in Bohr magnetons (when approximated to the nearest integer) is __________.

[Atomic number Fe = 26]

Compound(s) that on hydrogenation produce(s) optically inactive compound(s) is(are)