an element has two isotopes. calculate the (weighted) average atomic mass using the following data.\n%…

an element has two isotopes. calculate the (weighted) average atomic mass using the following data.\n% abundance mass\n72.172% 84.9117897 amu mass contribution is __1__ amu\n27.832% 86.9091805 amu mass contribution is __2__ amu\nthe average atomic mass is __3__ amu.\na. 84.9117897 b. 86.9091805 c. 85.471 d. 61.282537\ne. 24.188563 f. 6128.2537 g. 2418.8563 h. 8547.1

an element has two isotopes. calculate the (weighted) average atomic mass using the following data.\n% abundance mass\n72.172% 84.9117897 amu mass contribution is __1__ amu\n27.832% 86.9091805 amu mass contribution is __2__ amu\nthe average atomic mass is __3__ amu.\na. 84.9117897 b. 86.9091805 c. 85.471 d. 61.282537\ne. 24.188563 f. 6128.2537 g. 2418.8563 h. 8547.1

Answer

Explanation:

Step1: Calculate first mass - contribution

Multiply the first isotope's percentage abundance (in decimal form) by its mass. The first isotope has an abundance of 72.172% or 0.72172 in decimal form and a mass of 84.9117897 amu. So, the mass - contribution is $0.72172\times84.9117897\approx61.282537$ amu.

Step2: Calculate second mass - contribution

Multiply the second isotope's percentage abundance (in decimal form) by its mass. The second isotope has an abundance of 27.832% or 0.27832 in decimal form and a mass of 86.9091805 amu. So, the mass - contribution is $0.27832\times86.9091805\approx24.188563$ amu.

Step3: Calculate average atomic mass

Add the two mass - contributions together. $61.282537 + 24.188563=85.471$ amu.

Answer:

  1. D. 61.282537
  2. E. 24.188563
  3. C. 85.471