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 A 15.99 u 99.762% B 16.99 u 0.038% C 17.99 u 0.200%

The correct answer is option A 15.99 u 99.762% .

To calculate the weighted average atomic mass of the element, we'll use the formula:

Weighted Average Atomic Mass = (Mass of Isotope A * Percent Abundance of Isotope A) + (Mass of Isotope B * Percent Abundance of Isotope B) + (Mass of Isotope C * Percent Abundance of Isotope C)

Given:

Isotope A: Atomic Mass = 15.99 u, Percent Abundance = 99.762%

Isotope B: Atomic Mass = 16.99 u, Percent Abundance = 0.038%

Isotope C: Atomic Mass = 17.99 u, Percent Abundance = 0.200%

Let's calculate:

Weighted Average Atomic Mass=(15.99 u×99.762%)+(16.99 u×0.038%)+(17.99 u×0.200%)

First, convert the percentages to decimals (divide by 100):

99.762%=0.99762

0.038%=0.00038

0.200%=0.00200

Now, perform the calculation:

Weighted Average Atomic Mass=(15.99×0.99762)+(16.99×0.00038)+(17.99×0.00200)

Weighted Average Atomic Mass=15.95675738+0.00644262+0.03598

Adding these values together:

Weighted Average Atomic Mass=15.99918 u

Therefore, the weighted average atomic mass of the element is approximately 15.99918 u.