Identify the chemical formula of the compound, which is \(\mathrm{N_2O}\), meaning it contains 2 nitrogen atoms and 1 oxygen atom.
Find the atomic masses of nitrogen and oxygen from the periodic table: approximately 14.01 g/mol for nitrogen and 16.00 g/mol for oxygen.
Calculate the molar mass of \(\mathrm{N_2O}\) by summing the masses of all atoms: \(2 \times 14.01 + 1 \times 16.00\).
Calculate the total mass of nitrogen in the compound: \(2 \times 14.01\) g/mol.
Determine the percent by mass of nitrogen using the formula: \(\text{Percent by mass of N} = \left( \frac{\text{mass of N}}{\text{molar mass of } \mathrm{N_2O}} \right) \times 100\%\).