Answer:
Average atomic mass = 6.96 amu.
Explanation:
Abundance of Li-6 = 4%
Abundance of Li-7 = 96%
Atomic mass of Li-6 = 6 amu
Atomic mass of Li-7 = 7 amu
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (4×6)+(96×7) /100
Average atomic mass = 24 + 672 / 100
Average atomic mass = 696 / 100
Average atomic mass = 6.96 amu.
