Which of the following ions is identified as nitrate?

The ion identified as nitrate is represented by the formula NO3-. This ion consists of one nitrogen atom covalently bonded to three oxygen atoms, and it carries a negative one charge. Nitrate is a commonly found polyatomic ion in various chemical compounds, particularly in fertilizers and explosives.

Nitrate plays an essential role in biological systems, as it is a critical source of nitrogen, which is necessary for the synthesis of amino acids, proteins, and nucleic acids in living organisms. Understanding the structure and function of nitrate can help students grasp its significance in both environmental sciences and agricultural applications.

The other ions listed have distinct identities and functions: NO2- is nitrite, which has one less oxygen than nitrate; SO4 2- is sulfate, a completely different ion containing sulfur; and NH4+ is the ammonium ion, which contains nitrogen but is fundamentally different from nitrate in structure and charge. Recognizing these differences emphasizes the unique characteristics of nitrate.