Question

The average atomic mass represents the average of all the naturally occurring isotopes of the element.

• A. True
• B. False

Answer 1

The correct option is B False

The average atomic mass of an element represents the weighted average not the normal average of all the naturally occurring isotopes of the element.

For example: average atomic mass of chlorine is 35.5. In any sample of chlorine, the two isotopes of chlorine are ${\text{Cl}}^{35}$ and ${\text{Cl}}^{37}$ in an approximate ratio of 3:1.

Therefore, average atomic mass of chlorine :$\frac{3\left(35\right)+1\left(37\right)}{3+1}=35.5u$.