Final answer:
The naming system for polyatomic ions differing in oxygen atoms employs prefixes like 'per-' and 'hypo-', and suffixes '-ate' and '-ite', but due to inconsistencies, specific combinations must be memorized.
Step-by-step explanation:
The preferred system for naming polyatomic ions that differ in the number of oxygen atoms is to use the prefixes per- and hypo-. These prefixes, along with the suffixes -ate and -ite, help indicate the number of oxygen atoms in the ions.
For example, perchlorate is ClO4¯, indicating it has more oxygen atoms than chlorate (ClO3¯), while hypochlorite (ClO¯) has fewer oxygen atoms than chlorite (ClO2¯).
However, this naming system has inconsistencies, as the exact number of oxygen atoms does not always correlate directly with these prefixes and suffixes; therefore, memorization of specific ion name and formula combinations, such as nitrate (NO3¯) and sulfate (SO4²¯), is necessary.