The correct increasing order of the O-N-O bond angles in NO ₂^+ , NO ₂ , NO ₂^- and NO ₃^- is:

Step-by-step solution

To determine the bond angles, we examine the hybridization and the number of lone pairs/odd electrons on the central nitrogen atom in each species: 1. NO ₂^+ : The central nitrogen is sp hybridized with no lone pairs. The geometry is linear, giving a bond angle of 180^ . 2. NO ₃^- : The central nitrogen is sp^2 hybridized with no lone pairs. The geometry is trigonal planar, giving a bond angle of exactly 120^ . 3. NO ₂^- : The central nitrogen is sp^2 hybridized with one full lone pair. The lone pair-bond pair repu