hey, i have a hw problem that i dont know how to approach. Could you guys point me in theright direction? I dont want the answer, just a way to get started.

"The two naturally occruing isotopes of nitrogen have masses of 14.0031 and 15.0001, respectively. Determine the percentage of 15^N atoms in naturally occuring nitrogen.

 

Look at the atomic mass for N on the periodic table. That number is the average atomic mass of all existing N atoms. That includes those of both Isotopes.