The shortest bond length is generally found in molecules with the highest bond order, as bond length is inversely proportional to bond order. Triple bonds have shorter bond lengths than double or single bonds. For example, carbon- carbon triple bonds (~120 pm) are shorter than double bonds (~134 pm) or single bonds (~154 pm).

Among examples with different charged species, oxygen molecules with higher bond orders have shorter bond lengths: O2+ (bond order 2.5) has the shortest bond length compared to neutral O2 and other oxygen species. Similarly, N2 has the shortest bond length due to its triple bond and highest bond order among nitrogen species.

Without a specific list of options provided, the molecule or species with the highest bond order, such as a triple bond or positively charged species with fewer antibonding electrons, will have the shortest bond length.