b
\(NO _2\) involves an \(sp ^2\) type of hybridization. The most simple way to determine the hybridization of \(NO _2\) is by drawing the Lewis structure and counting the number of bonds and lone electron pairs around the nitrogen atom. You will find that in nitrogen dioxide there are \(2\) sigma bonds and \(1\) lone electron pair. Now if we apply the hybridization rule then it states that if the sum of the number of sigma bonds, lone pair of electrons, and odd electrons is equal to three then the hybridization is \(sp ^2\).