Here's a breakdown:
* Ion: An atom or molecule that has gained or lost electrons, resulting in a net electrical charge.
* Polyatomic: A molecule containing more than one atom.
Examples of polyatomic ions:
* Hydroxide ion (OH-): One oxygen atom and one hydrogen atom bonded together with a net negative charge.
* Nitrate ion (NO3-): One nitrogen atom and three oxygen atoms bonded together with a net negative charge.
* Ammonium ion (NH4+): One nitrogen atom and four hydrogen atoms bonded together with a net positive charge.
* Sulfate ion (SO4^2-): One sulfur atom and four oxygen atoms bonded together with a net negative charge.
Important Note: Polyatomic ions are often found in ionic compounds. They act as single units with a specific charge, just like individual ions.
