A naturally occurring element consists of two isotopes. The data for the isotopes are:
Isotope 1 68.5257 u 60.226 %
Isotope 2 70.9429 u ------ % Calculate the average atomic mass of this element. Hint: Percentages should always add up to 100% then find the weighted average.

Question

Quizplus · Accepted Answer

The average atomic mass is the weighted average of the masses of the isotopes, where the weights are the relative abundances of the isotopes. In this case, the average atomic mass is:(68.5257 u * 0.60226) + (70.9429 u * 0.39774) = 69.728 u

A Naturally Occurring Element Consists of Two Isotopes