Question

If $M$ is atomic weight, $A$ is mass number then $\frac{M-A}{A}$ represent

• A. Mass defect
• B. Packing fraction
• C. Binding Energy
• D. Nuclear density

Answer 1

The correct option is B Packing fraction

Packing fraction is defined as

$\frac{\text{Actual isotopic mass}-\text{Mass number}}{\text{Mass number}}$

$\Rightarrow \text{Packing fraction}=\frac{M-A}{A}$

$\to$ Packing fraction indicates the stability of a nucleus.

$\to$ Negative packing fraction indicates that the nucleus is stable.

$\to$ Positive packing fraction indicates that the nucleus is unstable.

Hence, option $\left(B\right)$ is correct.