Question

Assertion : The binding energy per nucleon, for nuclei with atomic mass number $A > 100$ decreases with $A$.
Reason : The nuclear forces are weak for heavier nuclei.

• A. If both assertion and reason are true and reason is the correct explanation of the assertion
• B. If both assertion and reason are true but reason is not the correct explanation of the assertion
• C. If assertion is true, but reason is false
• D. Both assertion and reason are false statements

Answer 1

Answer: (B)

The binding energy per nucleus is determined by dividing the binding energy of the nucleus by the number of nucleons it contains. Elements with intermediate atomic masses have the greatest binding energies per nucleon and are therefore the most stable.
The decrease in binding energy per nucleon for heavy nuclei $(A > 100)$ due to increase in coulomb repulsion between the protons inside the nucleus.