question_answer 17)

Calculate the atomic mass (average) of chlorine using the following data: % Natural Abundance Molar mass \[^{35}Cl\] 75.77 34.9689 \[^{37}Cl\] 24.23 36.9659  

Answer:

average atomic mass \[=\sum \frac{%\text{ Abundance}}{100}\times \text{Isotopic atomic mass}\] \[=\left[ \frac{75.77}{100}\times 34.9689 \right]+\left[ \frac{24.23}{100}\times 36.9659 \right]\] \[=26.4959+8.9568\] \[=35.45\,amu\]