The English used in this article may not be easy for everybody to understand. (August 2016)
Nitrogen normally has only three bonds. In a nitro group, the bond is considered positively charged. Then one bond of the oxygen is negatively charged, and the other has a double bond. In reality, the best way to represent the nitro group is to consider it to have delocalized electrons. Then all three atoms are sp2 hybridised.
Reaction[change | change source]
Nitro compounds are very explosive. This is because, at high temperature, nitro compounds can decompose and release nitrogen gas. This reaction is very exothermic (gives out a lot of energy). Many explosives have nitro groups, for example trinitrotoluene (TNT).