Final answer:
Sodium periodate is represented by the formula NaIO₄, which indicates the ionic compound formed from one sodium ion and one periodate ion.
Step-by-step explanation:
The structure for sodium periodate is represented by the chemical formula NaIO₄. This formula indicates that one sodium ion (Na+) combines with one periodate ion (IO₄⁻) to form the ionic compound sodium periodate. Hence, the correct option is (a) NaIO₄. Sodium periodate is often used in organic chemistry for the oxidation of certain organic compounds.