Question

The element bromine consists of two naturally occurring isotopes. The isotope with a mass of 78.92 amu has a percent abundance of 50.69%, while the isotope with a mass of 80.92 amu has a percent abundance of 49.31%. Calculate the average atomic mass of bromine.

Answer 1

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.