Final answer:
The relative atomic mass of bromine is approximately 79.9 amu.
Step-by-step explanation:
The relative atomic mass of an element is calculated by taking into account the mass and abundance of its isotopes. To calculate the average atomic mass of bromine, we can use the masses and abundances of its two naturally occurring isotopes, bromine-79 and bromine-81.
Given that bromine-79 has a mass of 79.904 amu with an abundance of 50.69%, and bromine-81 has a mass of 80.9163 amu with an abundance of 49.31%, we can calculate the average atomic mass using the formula:
Average atomic mass = (mass of isotope 1 * abundance of isotope 1) + (mass of isotope 2 * abundance of isotope 2)
Plugging in the values for bromine-79 and bromine-81, we get:
Average atomic mass = (79.904 amu * 0.5069) + (80.9163 amu * 0.4931)
Simplifying the equation, we find that the relative atomic mass of bromine is approximately 79.9 amu.