Final answer:
To calculate the percent abundance of the two isotopes of Boron, you need to use the concept of weighted average. You can rearrange the formula to solve for the percent abundance of each isotope and then solve the system of equations to find the percent abundances of the two isotopes.
Step-by-step explanation:
To calculate the percent abundance of the two isotopes of Boron, you need to use the concept of weighted average. The formula for calculating weighted average is:
Average = (% abundance of isotope 1 * mass of isotope 1) + (% abundance of isotope 2 * mass of isotope 2)
In this case, you are given the average atomic mass of Boron (10.81 amu) and the masses of the two isotopes (B-10, with a mass of 10 amu, and B-11, with a mass of 11 amu). So you can rearrange the formula to solve for the percent abundance of each isotope:
(% abundance of B-10) * 10 + (% abundance of B-11) * 11 = 10.81
Since you have two unknowns, you will need a second equation to solve the system. One possible equation is the sum of the percent abundances should add up to 100%:
% abundance of B-10 + % abundance of B-11 = 100%
Now you have a system of two equations that can be solved simultaneously to find the percent abundances of the two isotopes.