Question

Calculate the force between two fission fragments of equal masses and sizes that are produced by the fission of Pu²³⁹ by a thermal neutron in which four neutrons are emitted.

Answer 1

Total mass number of ₉₄Pu²³⁹ and a neutron = 246

Mass number of each fragment = 240 - 4/2 = 118

Charge on each fragment = 94/2 = 47

Radius of nucleus so formed = 1.2×10^–14 A^1/3 where A is the mass number

∴ r = 1.2×10^–15×(118)^1/3 = 5.886×10^–15 

Distance between the centres of two fragments = 2×5.886×10^–14 = 11.77×10^–15