Question

he average atomic mass of oxygen is 15.9994 amu. The atomic masses of its three isotopes are as follows:. . O-16: 15.995 amu; O-17: 16.999 amu; O-18: 17.999 amu. . Which isotope is most likely to have the greatest abundance in nature?

Answer 1

To calculate the average mass of the element, we take the summation of the product of the isotope and the percent abundance. Since we are given with the average atomic mass of 15.9994, the isotope with the greatest abundance has an atomic weight that should be closest to this number. This isotope is O-16.