1. Find the molar mass of NH₄NO₃:

* N (nitrogen): 14.01 g/mol * 2 = 28.02 g/mol

* H (hydrogen): 1.01 g/mol * 4 = 4.04 g/mol

* O (oxygen): 16.00 g/mol * 3 = 48.00 g/mol

Total molar mass of NH₄NO₃ = 28.02 + 4.04 + 48.00 = 80.06 g/mol

2. Calculate the moles of NH₄NO₃:

* moles = mass / molar mass

* moles = 10 g / 80.06 g/mol

* moles ≈ 0.125 mol

3. Determine the moles of nitrogen atoms:

* There are 2 nitrogen atoms per molecule of NH₄NO₃.

* moles of nitrogen = 0.125 mol NH₄NO₃ * (2 mol N / 1 mol NH₄NO₃)

* moles of nitrogen = 0.25 mol

4. Calculate the number of nitrogen atoms:

* Use Avogadro's number: 6.022 x 10²³ atoms/mol

* number of nitrogen atoms = 0.25 mol * 6.022 x 10²³ atoms/mol

* number of nitrogen atoms ≈ 1.51 x 10²³ atoms

Therefore, there are approximately 1.51 x 10²³ atoms of nitrogen in 10 g of NH₄NO₃.