## Chemistry and Chemical Reactivity (9th Edition)

Nitrogen is in group 15, having 5 valence electrons so $N_3^-$ has 16 Oxygen is in group 16, carbon in 14. $N_2O: 2×5+6=16$ $NO_2^+: 5+2×6-1=16$ $O_3: 3×6=18$ $CO_2: 4+6×2=16$