Question

A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding energy per nucleon of unfragmented nuclei is 7.6 MeV while that of fragments is 8.5 MeV. The total gain in the binding energy in the process is:

Options

• 216 MeV

• 0.9 MeV

• 9.4 MeV

• 804 MeV

Answer 1

216 MeV

Explanation:

Given,

Mass number of nucleus (m) = 240

The masses of two fragments are

m₁ = m₂ =120

Binding energy per nucleon of unfragmented nuclei = 7.6 MeV

BE of fragmented nuclei = 8.5 MeV

Total gain in Binding energy =?

Total gain in Binding energy = BE of products, BE of reactants

= (120 + 120) × 85 − 240 × 7.6 

= 240 × 85 − 240 × 7.6

= 216 MeV

Hence, gain in binding energy = 216 MeV.