Question

How do i solve the following question (please show work):
Oxygen has three naturally occurring isotopes in the following proportions: oxygen-16, 99.762% (15.994 91 amu); oxygen-17, 0.038000% (16.999 13 amu); oxygen-18, 0.20000% (17.999 16 amu). What is the average atomic mass of oxygen?

Answer 1

Eqn for finding average atomic mass is as following:
Average atomic mass=∑(relative isotopic mass × percentage abundance)

For qn:
Average atomic mass of oxygen= ∑(99.762×16) + (0.038000×17) + (0.20000×18)
=1600.438