Question

Which of the following figures correctly represents the shape of the curve of binding energy per nucleon as a function of mass number?

• A.
• B.
• C.
• D.

Hint:

The peak in the binding energy curve around \( A = 56 \) (Iron-56) explains why nuclear fission and fusion release energy—lighter elements fuse to move towards iron, and heavier elements split to move towards iron.

Answer 1

The Correct Option is B

The curve of binding energy per nucleon as a function of mass number is a fundamental concept in nuclear physics. The binding energy per nucleon is a measure of the stability of a nucleus. As per nuclear physics, the binding energy per nucleon generally increases with the mass number until a particular peak, after which it starts to decrease. 
The chart follows a specific trend:

• For lighter nuclei, the binding energy per nucleon increases rapidly with increasing mass number, as these smaller nuclei gain greater stability.
• This increase continues until we reach a peak at around mass numbers 56 to 58, corresponding to elements like iron and nickel. These elements are the most stable and have the highest binding energy per nucleon.
• After reaching this peak, the binding energy per nucleon gradually decreases for heavier nuclei. This is due to the increasing effect of the repelling force of protons at such high nucleon numbers, even though neutrons help to a certain extent to stabilize the nucleus.