Question

what are polymatic ions ? give examples also.

Answer 1

A polyatomic ion is a group of atoms carrying positive or negative charge.
Ammonium                                              NH4+

Hydroxide                                                OH–

Nitrate                                                     NO3–

Answer 2

Polymatic ions also known as molecular ion. Is a charged chemical species composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit.
examples are...
NO3