Question

what is a polyatomic ion? *
a single atom with multiple charges
a molecule with no charge
an atom with a single charge
a group of covalently bonded atoms that behaves as an ion

Explanation:

A polyatomic ion is defined as a group of covalently bonded atoms that behaves as an ion. A single atom with multiple charges is incorrect as polyatomic ions have multiple atoms. A molecule with no charge is not an ion. An atom with a single charge is a monatomic ion, not polyatomic.

Answer:

A group of covalently bonded atoms that behaves as an ion