Final answer:
The name of the polyatomic ion OH- is the hydroxide ion, which is an exception to the usual '-ate' and '-ite' suffix rules for polyatomic anions with oxygen.
Step-by-step explanation:
The polyatomic ion OH- is known as the hydroxide ion. Although most polyatomic anions with oxygen are known by their '-ate' or '-ite' suffixes depending on the number of oxygen atoms, the hydroxide ion is an exception where the '-ide' suffix indicates a single polyatomic anion. This ion is special because it doesn't fall within the series that differ by the number of oxygen atoms present. Instead, it is represented by its distinct formula OH- without varying numbers of oxygen atoms.
When writing the final formula for compounds containing the hydroxide ion, all subscripts of 1 are omitted, and parentheses are unnecessary if there is only 1 of the polyatomic ion present. For instance, sodium hydroxide would be written as NaOH, not Na(OH).