Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : The binding energy per nucleon is found to be practically independent of the atomic number A, for nuclei with mass numbers between 30 and 170. Reason (R): Nuclear force is long range. In the light of the above statements, choose the correct answer from the options given below :

Evaluate the assertion and reason about nuclear binding energy.

Assertion (A): The binding energy per nucleon is practically independent of A for nuclei with mass numbers between 30 and 170.

This is TRUE. The BE/nucleon curve is roughly flat (~8.5 MeV) in this range.

Reason (R): Nuclear force is long range.

This is FALSE. Nuclear force is SHORT range (about 1-2 femtometers). In fact, the saturation of binding energy per nucleon is a consequence of the short-range nature of nuclear force - each nucleon interacts only with its nearest neighbors.

The correct answer is Option 1: (A) is true but (R) is false.