Polyatomic positive ions often have common names ending with the suffix ______.

The correct answer is -onium.

Key Points

• -onium:-
  • It​ is a common suffix for polyatomic positive ions.
  • The "-onium" suffix is used to indicate that a cation is composed of two or more atoms, such as ammonium (NH4+) or phosphonium (PH4+).
  • This naming convention is useful for identifying and communicating the composition and charge of polyatomic ions in chemical reactions and other contexts. ​

Additional Information

• Polyatomic ions:-
  • These​ are ions that consist of two or more atoms that are covalently bonded or have a net positive or negative charge.
  • Common examples of polyatomic positive ions include ammonium (NH4+), hydronium (H3O+), and methylammonium (CH3NH3+).
• "-ium" :-
  • It is often added to the end of the name of a polyatomic positive ion to indicate that it is a cation (positively charged ion).
• "-ic" :-
  • ​It is commonly used to indicate the presence of an acid, while "-ous" is used to indicate a lower oxidation state of an element.
• "-ide":-
  • It​ is typically used to indicate an anion (negatively charged ion), such as chloride (Cl-) or oxide (O2-).