Answer
The atomic mass of the element is the average mass of the isotopes of the element.
Work Step by Step
It is a weighted average using the percent abundances and mass number of each isotope.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.