How NO2 structure is not valid?

Answer 1

The structure of nitrogen dioxide (NO2) is often misrepresented due to the presence of an odd number of valence electrons, resulting in an unpaired electron. This leads to a radical species that cannot be accurately depicted using traditional Lewis structures, which typically assume a stable electron pair configuration. Instead, the resonance forms of NO2 illustrate its actual structure, where one nitrogen-oxygen bond is a double bond, and the other is a single bond, with one unpaired electron contributing to its reactivity. Thus, relying solely on a static Lewis structure fails to capture the dynamic nature of this molecule.