Question

An element has three naturally occurring isotopes. Use the information below to calculate the weighted average atomic mass of the element, showing both the setup and the final answer for the calculation.

Isotope

Atomic Mass

Percent Abundance

X 1.01 u 99.984%

Y 2.01 u 0.014%

Z 3.02 u 0.002%

Answer 1

Weight average = 1.01 * 0.99984 + 2.01* 0.00014 + 3.02 * 0.00002

answer is 1 .0101802