. Boron has two isotopes
B - 10 and B - 11 , the average atomic mass of boron is found to be 10.80 u . Calculate the percentage of abundance of these isotopes.
We have been given the average mass of boron i.e. 10.80 u.
Now, we will let the abundance of B-10 be x% and that of B-11 be (100-x)%.
Now, we will calculate the average mass of boron,
Average mass of boron=x×10+(100-x)×11
So, the percentage abundance of B-10 is 20% and that of B-11 is 80%.
Hence, the percentage abundance of B-10 is 20% and that of B-11 is 80%.