What is the chemical formula for the ammonium ion?

The ammonium ion is represented by the formula NH4+. This designation indicates that the ion consists of one nitrogen atom and four hydrogen atoms. It carries a positive charge, resulting from the nitrogen atom forming an additional bond than it would in a neutral molecule, effectively gaining a hydrogen ion (H+). This is a common ion in chemistry, particularly in acid-base reactions and in various biological processes.

In contrast, NH3 refers to ammonia, which is a neutral molecule and does not carry any charge. N2H4, known as hydrazine, consists of two nitrogen atoms and four hydrogen atoms, making it a distinctly different compound. Lastly, NH2- represents the amide ion, which has a negative charge and is also different from the ammonium ion. Understanding these differences helps clarify how charge and molecular structure influence the identity of chemical species.