Final answer:
The average atomic mass of Lithium is approximately 6.93 amu.
Step-by-step explanation:
The average atomic mass of Lithium can be calculated by multiplying the mass of each isotope by its percentage abundance and summing the results. In this case, the atomic mass of 6Li is 6.01512 amu (amu stands for atomic mass unit) and the atomic mass of 7Li is 7.01600 amu. The percentage abundance of 6Li is 7.42% and the percentage abundance of 7Li is 92.58%. To calculate the average atomic mass, we can use the formula:
Average atomic mass = (6Li atomic mass x 6Li percentage abundance) + (7Li atomic mass x 7Li percentage abundance)
= (6.01512 amu x 0.0742) + (7.01600 amu x 0.9258) = 0.44607904 amu + 6.4858168 amu = 6.93189584 amu
Therefore, the average atomic mass of Lithium is approximately 6.93 amu.