Bromine consists of two major isotopes with the following percent abundances and atomic masses: 79Br (50.54% and 78.918 amu) and 81Br (49.46% and 80.916 amu). Calculate the average atomic mass of bromine.
(78.918*0.5054) + (80.916*0.4946) = x
Solve for x.
To calculate the average atomic mass of bromine, we can use the percent abundances and atomic masses of its isotopes. The average atomic mass is calculated as the weighted average of the atomic masses of each isotope, with the percent abundance as the weight.
The formula to calculate the average atomic mass is:
Average atomic mass = (percent abundance of isotope 1 * atomic mass of isotope 1) + (percent abundance of isotope 2 * atomic mass of isotope 2) + ...
In this case, we have two major isotopes of bromine:
Isotope 1: 79Br with a percent abundance of 50.54% and an atomic mass of 78.918 amu.
Isotope 2: 81Br with a percent abundance of 49.46% and an atomic mass of 80.916 amu.
Now let's calculate the average atomic mass of bromine:
Average atomic mass = (0.5054 * 78.918 amu) + (0.4946 * 80.916 amu)
Calculating this expression:
Average atomic mass = 39.99798 amu + 39.99789 amu
Adding the values:
Average atomic mass = 79.99587 amu
So, the average atomic mass of bromine is approximately 79.996 amu.
To calculate the average atomic mass of bromine, we need to multiply the mass of each isotope by its percent abundance and then sum up the results.
First, we calculate the contribution of each isotope to the average atomic mass:
For 79Br (50.54%):
Contribution = (Percent abundance / 100) * Atomic mass
Contribution = (50.54 / 100) * 78.918 amu = 39.8954112 amu
For 81Br (49.46%):
Contribution = (Percent abundance / 100) * Atomic mass
Contribution = (49.46 / 100) * 80.916 amu = 40.0071136 amu
Next, we add up the contributions of both isotopes:
Average atomic mass = Contribution of 79Br + Contribution of 81Br
Average atomic mass = 39.8954112 amu + 40.0071136 amu = 79.9025248 amu
Therefore, the average atomic mass of bromine is approximately 79.9025 amu.