<u>Answer:</u> The average atomic mass of element Zinc is 65.40 amu.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
- <u>For isotope:</u>
Mass of isotope = 63.929 amu
Percentage abundance of isotope = 48.63 %
Fractional abundance of isotope = 0.4863
- <u>For isotope:</u>
Mass of isotope = 65.926 amu
Percentage abundance of isotope = 27.90 %
Fractional abundance of isotope = 0.2790
- <u>For isotope:</u>
Mass of isotope = 66.927 amu
Percentage abundance of isotope = 4.10 %
Fractional abundance of isotope = 0.0410
- <u>For isotope:</u>
Mass of isotope = 67.925 amu
Percentage abundance of isotope = 18.75 %
Fractional abundance of isotope = 0.1875
- <u>For isotope:</u>
Mass of isotope = 69.925 amu
Percentage abundance of isotope = 0.62 %
Fractional abundance of isotope = 0.0062
Putting values in equation 1, we get:
Hence, the average atomic mass of element Zinc is 65.40 amu.