Q. Pick out the correct statement from the following.
A) Energy released per unit mass of the reactant is less in case of fusion reaction
B) Packing fraction may be positive or may be negative
C) $Pu^{239}$ is not suitable for a fission reaction
D) For stable nucleus, the specific binding energy is low
Explanation
(b) Mass defect per nucleon is called packing fraction. Packing fraction
$(f) = \frac{\mathrm{\Delta}m}{A} = \frac{m - A}{A}$ , 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.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.