# One isotope of bromine has an atomic mass of 78.92 amu and a relative abundance of 50.69%. The other major isotope of has an atomic mass of 80.92 amu and a relative abundance of 49.31%? What is the average atomic mass of bromine?

$\text{Average atomic mass of Br}$$=$$\left(78.92 \times 0.5069\right) + \left(80.92 \times 0.49331\right) = \text{79.92 u}$