Calculating isotope abundances
If the masses are known for the isotopes of a given element, it is also possible to compute the percent abundances by reversing the above procedure.
Example
- Calculate the percent abundances of copper-63 and copper-65 if the atomic weight is 63.54 amu and the exact masses of the isotopes are 63Cu = 62.93 amu and 65Cu = 64.93 amu. Assume no other isotopes exist.