Answer:
79.986
Step-by-step explanation:
Let A represent isotope ⁷⁹Br
Let B represent isotope ⁸¹Br
From the question given above, the following data were obtained:
For Isotope A (⁷⁹Br):
Mass of A = 79
Abundance of A (A%) = 50.69%
For isotope B (⁸¹Br):
Mass of B = 81
Abundance of B (B%) = 49.31%
Relative atomic mass of Br =?
The relative atomic mass (RAM) of Br can be obtained as follow:
RAM = [(Mass of A × A%) /100] + [(Mass of B × B%) /100]
= [(79 × 50.69) /100] + [(81 × 49.31) /100]
= 40.0451 + 39.9411
= 79.986 amu
Thus, the relative atomic mass of Br is 79.986