Respuesta :
Answer: The average atomic mass of bromine is 79.91 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)
For isotope 1:
Mass of isotope 1 = 78.92 amu
Percentage abundance of isotope 1 = 50.54 %
Fractional abundance of isotope 1 = 0.5054
For isotope 2:
Mass of isotope 2 = 80.92 amu
Percentage abundance of isotope 2 = 49.46 %
Fractional abundance of isotope 2 = 0.4946
Putting values in equation 1, we get:
[tex]\text{Average atomic mass of Bromine}=[(78.92\times 0.5054)+(80.92\times 0.4946)][/tex]
[tex]\text{Average atomic mass of Bromine}=79.91amu[/tex]
Hence, the average atomic mass of element bromine is 79.91 amu.