Lewis concept of ccovalency of an element involved octet rule. Later on it was found that may elements in their compounds e.g. BeF_(2),BF_(3) etc, have incomplete octet whereas PCl_(5), SF_(6) etcc. Have expanded octet. This classical concept also failed in predicting the geometry of molecules. Modern concept of covalence was proposed in terms of valence bond theory. Hybridization concept along with v.B. Theory successfully molecules was explained by VSEPR concept. Finally molecular orbital theory was proposed to explain many other molecules. The bond angles NO_(2)^(+), NO_(2) and NO_(2)^(-) are respectively.

Lewis concept of ccovalency of an element involved octet rule. Later o

1.	Lewis concept of ccovalency of an element involved octet rule. Later on it was found that may elements in their compounds e.g. BeF_(2),BF_(3) etc, have incomplete octet whereas PCl_(5), SF_(6) etcc. Have expanded octet. This classical concept also failed in predicting the geometry of molecules. Modern concept of covalence was proposed in terms of valence bond theory. Hybridization concept along with v.B. Theory successfully molecules was explained by VSEPR concept. Finally molecular orbital theory was proposed to explain many other molecules. The bond angles NO_(2)^(+), NO_(2) and NO_(2)^(-) are respectively.
Answer» `180^(@), 134^(@), 115^(@)` `115^(@), 134^(@), 180^(@)` `134^(@), 180^(@), 115^(@)` `115^(@), 180^(@), 130^(@)` Solution :Greater the no. of LONE pair on N-atom, SMALLER will be the bond angle.