Bromine has two isotopes 79br and 81br, whose masses (78.9183 and 80.9163 amu) and abundances (50.69% and 49.31%, respectively) were determined in earlier experiments. calculate the average atomic mass of bromine based on these experiments.

Average atomic mass = 79.9034 amu

Explanation:

The formula for the calculation of the average atomic mass is:

Given that:

For first isotope:

% = 50.69 %

Mass = 78.9183 amu

For second isotope:

% = 49.31 %

Mass = 80.9163 amu

Thus,  

Average atomic mass = 79.9034 amu

for points guys

the answer is either b or c