To determine how many nitrogen atoms are present in one formula unit of ammonium nitrate [tex]\((NH_4NO_3)\)[/tex], let's examine the composition of the molecule.
1. Identify the constituent ions in ammonium nitrate:
- Ammonium nitrate is composed of [tex]\(NH_4^+\)[/tex] (Ammonium ion) and [tex]\(NO_3^-\)[/tex] (Nitrate ion).
2. Count the nitrogen atoms in each ion:
- The [tex]\(NH_4^+\)[/tex] ion contains 1 nitrogen atom because the formula is [tex]\(NH_4^+\)[/tex].
- The [tex]\(NO_3^-\)[/tex] ion contains 1 nitrogen atom because the formula is [tex]\(NO_3^-\)[/tex].
3. Add the nitrogen atoms from both ions:
- One nitrogen atom from the [tex]\(NH_4^+\)[/tex] ion.
- One nitrogen atom from the [tex]\(NO_3^-\)[/tex] ion.
4. Calculate the total number of nitrogen atoms in one formula unit of ammonium nitrate:
- [tex]\(1 \text{ (from } NH_4^+ \text{ ion)} + 1 \text{ (from } NO_3^- \text{ ion)} = 2 \text{ nitrogen atoms}\)[/tex]
Hence, the number of nitrogen atoms present in one formula unit of ammonium nitrate is:
[tex]$2 \text{ atoms}$[/tex]
Thus, the correct answer is:
[tex]$\boxed{2 \text{ atoms}}$[/tex]