Answer
a) Hypoiodite Ion
b) Iodite Ion
c) Iodate Ion
d) Periodate Ion
Work Step by Step
a) Since the first poly atomic ion contains only one oxygen atom (the least compared to the other three polyatomic ions), it must have one less oxygen than the "ite" ion. Thus, the hypo- prefix, meaning one oxygen atom fewer than for -"ite" is added on to the name and the suffix remains "ite" so Hypoiodite ion.
b) The next poly-atomic ion contains one more oxygen than the hypoiodite ion but one less than the iodate ion which has 3 oxygen so its simply iodite ion.
c) The iodate ion is the most common poly-atomic ion for this group so the third one is simply iodate ion.
d) Since the last ion has one more oxygen than the "ate" ion, the per- prefix, meaning one more oxygen atom than an -ate molecule must be used and the suffix remains "ate". Therefore, periodate ion is the answer.