Answer: The abundance of Li-7 isotope is higher as compared to Li-6.
Explanation:
Average atomic mass is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
We are given:
Two isotopes of lithium :
Li-6 and Li-7
Average atomic mass of lithium= 6.941
As, the average atomic mass of lithium is closer to the mass of isotope Li-7. This means that the relative abundance of Li-7 is higher as compared to Li-6.
Percentage abundance of Li-7> Percentage abundance of Li-6 isotope