What is the formula for bromate?

The formula for bromate is BrO3(-). This ion is a polyatomic ion consisting of one bromine atom and three oxygen atoms. The negative charge indicates that the ion carries a -1 charge, which is typical for oxyanions of halogens where the central atom (in this case, bromine) is surrounded by several oxygen atoms.

In this formula, the presence of three oxygen atoms bonded to a single bromine atom is characteristic of the bromate ion. Oxyanions are formed when oxygen atoms bond with central atoms, and for halogens like bromine, the most common oxidation states lead to the formation of ions such as bromate.

This understanding reflects the systematic naming and formula creation in inorganic chemistry, where the naming conventions describe the configurations and charges of the ions. Other given choices either reflect incorrect formulas or correspond to different ions, which do not apply to bromate.