The element bromine, Br (atomic number 35), has two major isotopes of similar abundance, both about 50%. The atomic mass of bromine is reported in the periodic table as XXXXXXXXXXatomic mass units....

The element bromine, Br (atomic number 35), has two major isotopes of similar abundance, both about 50%. The atomic mass of bromine is reported in the periodic table as 79.904 atomic mass units. Choose the most likely set of mass numbers for the bromine isotopes: (a) Br-79, Br-81; (b) Br-79, Br-80; (c) Br-80, Br-81.