got the answer
i need help with this problem.
1)Calculate the mass of Br-79 using four sig fig.Bromine has two naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu. The mass of Br-81 is 80.9163 amu, and its natural abundance is 49.31%
2)Calculate the natural abundance of Br-79.