Polyatomic ion (original) (raw)

A polyatomic ion is an ion consisting of multiple atoms associated together by covalent bonds which can be considered as acting as a single unit in the context of acid/base chemistry or in the formation of salts. Note that in this context, a polyatomic ion is also referred to as a radical.

Some commonly-occurring polyatomic ions and their charge ub>2-

bicarbonate HCO3-

nitrate NO3-

phosphate PO43-

sulfate SO42-

acetate CH3C(=O)O-c2h3o2

ammonium NH4+

hydroxide OH-

pyridinium C5H5NH+

The atoms of a polyatomic ion are always associated with each other via covalent or coordinate-covalent bondss.

A polyatomic ion that is primarily associated with other atoms by covalent, rather than ionic, forces might more properly be referred to as afunctional group.

Note that many of the common negatively-charged (anionic) polyatomic ions are oxides of non-metallic elements, and can be considered the conjugate bases of the corresponding acids.