Question

²³⁵U is readily made fissionable by a thermal neutron but ²³⁸U is not because: 

A. the neutron has a smaller binding energy in ²³⁶U 

B. the neutron has a smaller excitation energy in ²³⁶U 

C. the potential barrier for the fragments is less in ²³⁹U 

D. the neutron binding energy is greater than the barrier height for ²³⁶U and less than the barrier height for ²³⁹U 

E. the neutron binding energy is less than the barrier height for ²³⁶U and greater than the barrier height for ²³⁹U

Answer 1

D. the neutron binding energy is greater than the barrier height for ²³⁶U and less than the barrier height for ²³⁹U