Erchlorates are powerful oxidizing agents used in fireworks, flares, and space shuttle booster rockets. Lewis structures for the perchlorate ion (ClO4−) can be drawn with all single bonds or with one, two, or three double bonds. Draw each of these possible resonance forms, including any nonbonding electrons. Include the values of any nonzero formal charges. Use formal charges to determine the most important resonance structure and calculate its average bond order.