Final answer:
To calculate the average atomic mass of bromine, multiply the mass of each isotope by its percent abundance and add the results. The average atomic mass of bromine is approximately 79.9318 amu.
Step-by-step explanation:
To calculate the average atomic mass of bromine, we need to multiply the mass of each isotope by its percent abundance and then add the results.
For the isotope with a mass of 78.92 amu and a percent abundance of 50.69%, the contribution to the average atomic mass is:
Contribution 1: 78.92 amu * 0.5069 = 39.992948 amu
For the isotope with a mass of 80.92 amu and a percent abundance of 49.31%, the contribution to the average atomic mass is:
Contribution 2: 80.92 amu * 0.4931 = 39.938852 amu
Adding the two contributions together gives:
39.992948 amu + 39.938852 amu = 79.9318 amu
Therefore, the average atomic mass of bromine is approximately 79.9318 amu.