What is the chemical formula for nitrogen dioxide?

The chemical formula for nitrogen dioxide is indeed represented as NO2. To break this down, nitrogen is the central atom, and it can form various compounds with oxygen. In nitrogen dioxide, one nitrogen atom is bonded to two oxygen atoms, which is indicated by the subscript '2' following the 'O' in the formula.

This formula reflects the molecular composition of nitrogen dioxide where the naming conventions in chemistry dictate that prefixes or subscripts indicate the number of each type of atom present in a molecule. In this case, the 'di-' prefix in the name "nitrogen dioxide" also suggests the presence of two oxygen atoms bonded to nitrogen. This understanding of chemical nomenclature helps reinforce the accuracy of the chemical formula.

The other options represent different chemical species. NO is nitrogen monoxide, which has one nitrogen and one oxygen atom; N2O is dinitrogen monoxide, comprising two nitrogen atoms and one oxygen atom; and N2O4 is dinitrogen tetroxide, which consists of two nitrogen atoms and four oxygen atoms. Each of these has a different molecular structure and properties compared to nitrogen dioxide.