Final answer:
Polyatomic ions are electrically charged molecules composed of two or more atoms bonded by covalent bonds. They act as discrete units and have characteristic formulas, names, and charges. Important examples include nitrate, carbonate, and ammonium.
Step-by-step explanation:
Polyatomic ions are electrically charged molecules composed of two or more atoms bonded by covalent bonds. Unlike monatomic ions, which are formed from only one atom, polyatomic ions act as discrete units.
Some of the more important polyatomic ions include nitrate (NO3-), carbonate (CO32-), and ammonium (NH4+). These ions have characteristic formulas, names, and charges that should be memorized in chemistry studies.