The only polyatomic ion with a plus 1 charge is the ammonium ion, which is represented as NH₄⁺.
Ammonium is formed when ammonia (NH₃) accepts a proton (H⁺). This addition of a hydrogen ion (proton) gives the ammonium ion its positive charge. Polyatomic ions are groups of atoms that behave as a single unit with a net charge, and ammonium is unique among them because it carries a positive charge, whereas most other polyatomic ions carry a negative charge. The significance of ammonium in the biological and chemical processes cannot be overstated, as it plays a crucial role in nitrogen metabolism and is essential for the production of fertilizers.