Binding energy per nucleon relation with mass number

Question

Binding energy per nucleon relation with mass number (A) first decreases then increases (B) first increases then decreases (C) increases (D) decreases

Tardigrade Admin · Accepted Answer

The variation of average binding energy per nucleon with mass number A is shown in figure.

Average binding energy per nucleon for light nuclei like

_{1} H^{1},_{1} H^{2},_{1} H^{3}

is small. For mass numbers ranging from 2 to 20, there are sharply defined peaks corresponding to

_{2} H e^{4},_{6} C^{12},_{8} O^{16} e t c .

The binding energy curve has a broad maximum in the range A = 30 to A = 120 corresponding to average binding energy per nucleon = 8.5 MeV. The peak value of the maximum is 8.8 MeV/nucleon for

_{26} F e^{56} .

As the mass number increases, the binding energy per nucleon decreases gradually falling to about 7.6 MeV per nucleon for

_{92} U^{238} .

Q. Binding energy per nucleon relation with mass number

first decreases then increases

first increases then decreases

increases

decreases