Structural isomers are molecules that have the same composition but a different pattern of connectivity. Two isomers of disulfur difluoride, S₂ F₂, are known. In each, the two S atoms are bonded to each other. In one isomer, each of the S atoms is bonded to an F atom. In the other isomer, both F atoms are attached to one of the S atoms.

(a) In each isomer, the S—S bond length is approximately 190 pm. Are the SOS bonds in these isomers single bonds, or do they have some double bond character?

(b) Draw two resonance structures for each isomer.

(c) Determine for each isomer which structure is favored by formal-charge considerations. Are your conclusions consistent with the S—S bond lengths in the compounds?