This species is added to starch to convert it to the paper additive di·aldehyde starch. Like an iso·electronic metalloid analog, this species converts between an octahedral ortho form and a tetrahedral meta form. When using organic solvents in which this species is insoluble, lead tetra·acetate can produce similar transformations. In an ozonolysis-like reaction, this ion both performs cleavage, and regenerates osmium tet·roxide. This ion reacts with poly·saccharides and glyco·proteins to produce functional groups that react with Schiff stain. A cyclic ester of this ion forms when its sodium salt (*) cleaves a glycol into two carbonyl compounds. Tellurates are isoelectronic to this anion. An often-mispronounced acid’s conjugate base is, for 10 points, what highest oxyanion of iodine, with formula IO4-? ■END■ (10[2])