Hi, When drawing the resonance structures for ClO-, two exist. One where the O has a formal charge of -1 and there is then a single bond. The other structure is Cl with -1 for formal charge. Why is this second structure an equal resonance structure (why does the Cl have a negative formal charge) when O has the higher electronegativity? Also, my next question stem from the previous one. In ClO4-, you have 4 resonance structures where the negative formal charge alternates between the 4 oxygen atoms, and the average bond order is 7/4. Why does a fifth resonance structure not exist where the chlorine has the negative formal charge, and makes a double bond with EACH oxygen atom? It seems like Cl can have a negative formal charge in ClO- and not ClO4-, and I would like an explanation for that, if possible. Thanks!