Answer:
[tex]NO_{2}[/tex]
Explanation: The empirical formula of a compound is the simplest whole number ratio of atoms in the compound. In [tex]N_{3} O_{6}[/tex], the ratio of N atoms to O atoms is 3:6, which can be reduced to 1:2. Using the reduced ratio, put new subscripts on the compound: [tex]N_{1} O_{2}[/tex]. Since subscript of 1 on the N is implied, no subscript needs to be written on the N, and the empirical formula is simply [tex]NO_{2}[/tex].
