Ammonia has a formula mass of 17.03 amu, with one nitrogen atom of 14.01 amu. What is the mass percentage of nitrogen in NH3?

1. One NH3 molecule holds one nitrogen atom of 14.01 amu and three hydrogen atoms of 3.024 amu in total. 2. The formula mass is 14.01 + 3.024 = 17.03 amu. 3. The nitrogen percentage is 14.01 amu / 17.03 amu x 100 percent. 4. That works out to 82.27 percent nitrogen. 5. The value 17.76 percent is the hydrogen share, from 3.024 / 17.03. _Source: OpenStax Chemistry (CC BY 4.0), Ch 3 "Composition of Substances and Solutions", section 3.2 Determining Empirical and Molecular Formulas_