Answer: The average atomic mass of copper is 63.546 amu
Explanation:
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:
[tex]\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i[/tex] .....(1)
Mass of isotope 1 = 62.93 amu
Percentage abundance of isotope 1 = 69.2 %
Fractional abundance of isotope 1 = 0.692
Mass of isotope 2 = 64.93 amu
Percentage abundance of isotope 2 = 30.8 %
Fractional abundance of isotope 2 = 0.308
Putting values in equation 1, we get:
[tex]\text{Average atomic mass of Copper}=[(62.93\times 0.692)+(64.93\times 0.308)]\\\\\text{Average atomic mass of Copper}=63.546amu[/tex]
Hence, the average atomic mass of copper is 63.546 amu