3) calculate the average atomic mass of lithium (li), which occurs ⁶li (abundance 7.30%) and ⁷li (abundance…

3) calculate the average atomic mass of lithium (li), which occurs ⁶li (abundance 7.30%) and ⁷li (abundance 92.70%).
Answer
Explanation:
Step1: Convert percentages to decimals
$7.30% = 0.0730$, $92.70%=0.9270$
Step2: Multiply isotope mass by abundance
The mass of $^{6}Li$ is approximately 6 amu and the mass of $^{7}Li$ is approximately 7 amu. For $^{6}Li$: $6\times0.0730 = 0.438$ For $^{7}Li$: $7\times0.9270=6.489$
Step3: Calculate average atomic mass
$0.438 + 6.489=6.927$
Answer:
$6.927$ amu