Question

Pick out the correct statement from the following:

• A. $Pu^{239}$ is not suitable for a fission reaction.
• B. For stable nucleus, the specific binding energy is low.
• C. Energy released per unit mass of the reactant is less in case of fusion reaction.
• D. Packing fraction may be positive or may be negative

Answer 1

Answer: (D)

Packing fraction may be positive or may be negative

Answer 2

Mass defect per nucleon is called packing fraction. Packing fraction $(f)=\frac{\Delta m}{A}=\frac{m-A}{A}$, where $m=$ mass of nucleus, $A=$ mass number. Packing fraction measures the stability of a nucleus. Smaller the value of packing fraction, larger is the stability of nucleus. Packing fraction may be positive, negative or zero.