Final answer:
To calculate the atomic mass of nitrogen, you need the atomic masses and the percent natural abundances of its isotopes, nitrogen-14 and nitrogen-15. Multiplying each isotope's atomic mass by its abundance and adding the products provides the atomic mass of the element.
Step-by-step explanation:
To calculate the atomic mass of nitrogen, or any element, information about the relative abundance (percent natural abundance) and the atomic masses of its isotopes is needed. For instance, if we have two isotopes of nitrogen, nitrogen-14 (N-14) with an atomic mass approximately 14 amu and nitrogen-15 (N-15) with an atomic mass approximately 15 amu, and their respective natural abundances, we can calculate the average atomic mass. This calculation is done by multiplying the atomic mass of each isotope by its relative abundance and then summing these values. For example, if nitrogen consisted of 80% N-14 and 20% N-15, you would calculate (14 amu * 0.80) + (15 amu * 0.20) to find the weighted average atomic mass.