The nuclear force is a short range force, this can be explained by fact that the binding energy per nucleon versus mass number curve
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → is flat for mass numbers in the range from 30 to 170.
Yes, the binding energy per nucleon is approximately constant for nuclei with mass numbers between 30 and 170. This is due to short-range nature of Nuclear force.