what is an polyatomic ion
A polyatomic ion, also known as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit. The prefix poly-means many, in Greek, but even ions of two atoms are commonly referred to as polyatomic.ts chemical formula is O H â . An ammonium ion is made up of one nitrogen atom and four hydrogen atoms: it has a charge of +1, and its chemical formula is N H 4 + . Polyatomic ions are often useful in the context of acid-base chemistry or in the formation of salts.